Ray - help on monitoring drive cycle of CAT(O2 sensor)

I subscribed to Toyota's techinfo.com, and due to the copy right so I
cannot post the info here. But I have a bunch of questions in order to
understand steps described by techinfo.com. My car is 2001 Corolla CE.
1) How you determine Coolant temp reaches 167F after start up? I
don't think my car has temp monitor on dash-board.
2) what is the second gear on my car? I have P, R, N, D, 2 and L
settings on shift and I have no idea what second gear means
3) Keep the accelerator pedal "off-idle", what does it mean?
My - guess - keep pressing it?
4) what is "execute fuel-cut"?
My guess - step on brake?

Thanks.

<wenmang@yahoo.com> wrote in message
news:1158525426.646013.101050@m73g2000cwd.googlegroups.com...[color=blue]
>I subscribed to Toyota's techinfo.com, and due to the copy right so I
> cannot post the info here. But I have a bunch of questions in order to
> understand steps described by techinfo.com. My car is 2001 Corolla CE.
> 1) How you determine Coolant temp reaches 167F after start up? I
> don't think my car has temp monitor on dash-board.[/color]

To check coolant temperature precisely, you have to use a thermometer to
check coolant temperature. For the purposes of making sure that the engine
is sufficiently warmed up, you can check the temperature gauge in the
instrument panel and see if it is around half way. I would imagine that
your car has a temperature gauge in the instrument panel, if it does not, a
half-hour drive should be more than sufficient to get things warmed up.
[color=blue]
> 2) what is the second gear on my car? I have P, R, N, D, 2 and L
> settings on shift and I have no idea what second gear means[/color]

Putting the shifter in the "L" position keeps the car in 1st gear.

Putting the shifter in the "2" position allows the transmision to shift from
1-2 and vice versa.

Putting the shifter in "D" with the "OD Off" light illuminated allows the
transmission to shift from 1-2-3 and vice versa.

Putting the shifter in "D" with the "OD Off" light extinguished allows the
transmissin to shift through all the gears.

To put the transmission in second gear, select the 2 range.
[color=blue]
> 3) Keep the accelerator pedal "off-idle", what does it mean?
> My - guess - keep pressing it?[/color]

"Off idle" means and engine RPM (engine speed) higher than when the throttle
pedal is not depressed. If you are checking the O2 sensor, engine RPM
should be around 2,000 RPM, or about the engine speed for 30 MPH in second
gear or about 50 MPH in D.
[color=blue]
> 4) what is "execute fuel-cut"?
> My guess - step on brake?
>
> Thanks.
>[/color]

"Fuel cut" is when the computer shuts off the flow of fuel to the fuel
injectors. Taking your foot off the throttle pedal and stepping on the
brake should activate fuel cut.
--

Ray O
(correct punctuation to reply)

[color=blue][color=green]
> > 2) what is the second gear on my car? I have P, R, N, D, 2 and L
> > settings on shift and I have no idea what second gear means[/color]
>
> Putting the shifter in the "L" position keeps the car in 1st gear.
>
> Putting the shifter in the "2" position allows the transmision to shift from
> 1-2 and vice versa.
>
> Putting the shifter in "D" with the "OD Off" light illuminated allows the
> transmission to shift from 1-2-3 and vice versa.
>
> Putting the shifter in "D" with the "OD Off" light extinguished allows the
> transmissin to shift through all the gears.
>
> To put the transmission in second gear, select the 2 range.
>[color=green]
> > 3) Keep the accelerator pedal "off-idle", what does it mean?
> > My - guess - keep pressing it?[/color]
>[/color]

Ray,
thanks very much for the answers. Stupid enough, I still have trouble
to understand what you just described about "second gear"- be precise
"select the 2 range". One of steps in techinfo.com asks to "select
second gear", could you please put it in plain english how I am going
to do that? is it just to shift the shifter to marked "2" position?
Sorry, being so stupid.
Thanks again.

<wenmang@yahoo.com> wrote in message
news:1158531916.631275.103720@i42g2000cwa.googlegroups.com...[color=blue]
>
>[color=green][color=darkred]
>> > 2) what is the second gear on my car? I have P, R, N, D, 2 and L
>> > settings on shift and I have no idea what second gear means[/color]
>>
>> Putting the shifter in the "L" position keeps the car in 1st gear.
>>
>> Putting the shifter in the "2" position allows the transmision to shift
>> from
>> 1-2 and vice versa.
>>
>> Putting the shifter in "D" with the "OD Off" light illuminated allows the
>> transmission to shift from 1-2-3 and vice versa.
>>
>> Putting the shifter in "D" with the "OD Off" light extinguished allows
>> the
>> transmissin to shift through all the gears.
>>
>> To put the transmission in second gear, select the 2 range.
>>[color=darkred]
>> > 3) Keep the accelerator pedal "off-idle", what does it mean?
>> > My - guess - keep pressing it?[/color]
>>[/color]
>
> Ray,
> thanks very much for the answers. Stupid enough, I still have trouble
> to understand what you just described about "second gear"- be precise
> "select the 2 range". One of steps in techinfo.com asks to "select
> second gear", could you please put it in plain english how I am going
> to do that? is it just to shift the shifter to marked "2" position?
> Sorry, being so stupid.
> Thanks again.
>[/color]

By "select the 2 range" I meant just shift the shifter to the position
marked "2."

Don't worry, I don't consider your question stupid ;-)

Sherlock Holmes used to say that the human brain has a finite capacity to
store knowledge, and I agree. Cars, machinery, and construction fascinate
me, and so I used to change light fixtures, plaster walls, and tinker with
the lawnmower since I was around 10. This fascination with cars and
machinery helped me a lot when I worked for an automaker, and a basic
understanding of construction has helped me as a commercial real estate
broker.

On the other hand, tulips, roses, dandelions, chrysanthemums, and daisies
are about the limit ability to identify flowers, while my business partner
can name just about any flower she sees and can name popular Korean soap
opera stars but after 20 years in the business, does not know the difference
between a trenched and a formed footing.

I would imagine that you have interests and knowledge in areas I know little
or nothing about.
--

Ray O
(correct punctuation to reply)

Ray O wrote:[color=blue]
> <wenmang@yahoo.com> wrote in message
> news:1158531916.631275.103720@i42g2000cwa.googlegroups.com...[color=green]
> >
> >[color=darkred]
> >> > 2) what is the second gear on my car? I have P, R, N, D, 2 and L
> >> > settings on shift and I have no idea what second gear means
> >>
> >> Putting the shifter in the "L" position keeps the car in 1st gear.
> >>
> >> Putting the shifter in the "2" position allows the transmision to shift
> >> from
> >> 1-2 and vice versa.
> >>
> >> Putting the shifter in "D" with the "OD Off" light illuminated allows the
> >> transmission to shift from 1-2-3 and vice versa.
> >>
> >> Putting the shifter in "D" with the "OD Off" light extinguished allows
> >> the
> >> transmissin to shift through all the gears.
> >>
> >> To put the transmission in second gear, select the 2 range.
> >>
> >> > 3) Keep the accelerator pedal "off-idle", what does it mean?
> >> > My - guess - keep pressing it?
> >>[/color]
> >
> > Ray,
> > thanks very much for the answers. Stupid enough, I still have trouble
> > to understand what you just described about "second gear"- be precise
> > "select the 2 range". One of steps in techinfo.com asks to "select
> > second gear", could you please put it in plain english how I am going
> > to do that? is it just to shift the shifter to marked "2" position?
> > Sorry, being so stupid.
> > Thanks again.
> >[/color]
>
> By "select the 2 range" I meant just shift the shifter to the position
> marked "2."
>
> Don't worry, I don't consider your question stupid ;-)
>
> Sherlock Holmes used to say that the human brain has a finite capacity to
> store knowledge, and I agree. Cars, machinery, and construction fascinate
> me, and so I used to change light fixtures, plaster walls, and tinker with
> the lawnmower since I was around 10. This fascination with cars and
> machinery helped me a lot when I worked for an automaker, and a basic
> understanding of construction has helped me as a commercial real estate
> broker.
>
> On the other hand, tulips, roses, dandelions, chrysanthemums, and daisies
> are about the limit ability to identify flowers, while my business partner
> can name just about any flower she sees and can name popular Korean soap
> opera stars but after 20 years in the business, does not know the difference
> between a trenched and a formed footing.
>
> I would imagine that you have interests and knowledge in areas I know little
> or nothing about.
> --
>
> Ray O
> (correct punctuation to reply)[/color]

Feel grateful, thanks again.

Ray,
I have more questions to ask before I carry out O2S readiness drive
test:
1) I bought a OBD2 reader(INNOVA) from WalMart, so far following
Monitor icons are complete on my car:
O - O2 sensor monitor
OH - O2 sensor heater monitor
Plus all other monitors except following one that is not done:
C - catalyst monitor which is currently blinking(not ready)
I am confused about "catalyst monitor", is it related to the drive
cycle we are talking about?
2) what does it mean "Vehicle is in closed loop"?
3) what is definition of one driving cycle?
4) since only "catalyst monitor" is no ready, should I skip the O2S
monitor(first couple of steps from techinfo.com seems for front O2
test) and directly go to the "rear O2S readiness monitor"(the one
using gear 2)?

I like to make sure that I understand everything correctly before I do
the test and I am not sure what stage my car is at.
Thx.

<wenmang@yahoo.com> wrote in message
news:1158541726.366596.263700@i3g2000cwc.googlegroups.com...[color=blue]
> Ray,
> I have more questions to ask before I carry out O2S readiness drive
> test:
> 1) I bought a OBD2 reader(INNOVA) from WalMart, so far following
> Monitor icons are complete on my car:
> O - O2 sensor monitor
> OH - O2 sensor heater monitor
> Plus all other monitors except following one that is not done:
> C - catalyst monitor which is currently blinking(not ready)
> I am confused about "catalyst monitor", is it related to the drive
> cycle we are talking about?[/color]

Probably, yes.
[color=blue]
> 2) what does it mean "Vehicle is in closed loop"?[/color]

The O2 sensors only provide valid readings if A) the O2 sensor is working,
B) the O2 sensor is warmed up, C) the vehicle is fully warmed up, and D) the
engine is not operating at wide open throttle (WOT) or close to WOT.

Since the O2 sensor only provides valid readings if all of the conditions
are met, for the conditions where all of those conditions are not met, like
when the vehicle is first started or under heavy acceleration, the computer
ignores O2 sensor output and relies on input from other sensors to determine
how much fuel to mix with the air.

When the computer is using O2 sensor output, the system is referred to being
in "closed loop" mode because it looks at O2 sensor readings to adjust the
air-fuel mixture, then looks at the result of the mixture adjustment, then
does the same thing over and over. The engine is operating most efficiently
fuel-consusmption and emissions-wise when the system is in closed loop. In
order to speed up the warmup process, the O2 sensors have heaters built in,
and the automatic transmission will not shift into overdrive until the
coolant temp is sufficiently warmed up.

In all other operating conditions, the system is referred to as being in
"open loop" because it is operating without O2 sensor input.
[color=blue]
> 3) what is definition of one driving cycle?[/color]

One driving cycle is one trip where the car is started and driven so that
every sensor monitored by the OBD II system has sent a valid signal to the
computer. Many OBD II diagnostic trouble codes (DTC) have a 2-trip
detection logic where it has to see the same fault for 2 consecutive trips
before it sets the malfunction indicator light (MIL, or check engine light),
and if it does not see the fault for 2 consecutive trips, it will turn off
the MIL.

The conditions that determine what counts as a "trip" or driving cycle vary
by vehicle, but they generally require a cold start, driving at various
specified speeds for a specified lengths of time, with the coolant temp
rising to a specified amount and the transmission shifting up and down
through all the gears for a specified amount of time, then parking the car
for a certain amount of time, then repeating the trip.
[color=blue]
> 4) since only "catalyst monitor" is no ready, should I skip the O2S
> monitor(first couple of steps from techinfo.com seems for front O2
> test) and directly go to the "rear O2S readiness monitor"(the one
> using gear 2)?[/color]

Yes. The catalyst monitor is the O2 sensor that is after the catalytic
converter.[color=blue]
>
> I like to make sure that I understand everything correctly before I do
> the test and I am not sure what stage my car is at.
> Thx.
>[/color]

--

Ray O
(correct punctuation to reply)

>[color=blue][color=green]
> > 2) what does it mean "Vehicle is in closed loop"?[/color]
>
> The O2 sensors only provide valid readings if A) the O2 sensor is working,
> B) the O2 sensor is warmed up, C) the vehicle is fully warmed up, and D) the
> engine is not operating at wide open throttle (WOT) or close to WOT.
>
> Since the O2 sensor only provides valid readings if all of the conditions
> are met, for the conditions where all of those conditions are not met, like
> when the vehicle is first started or under heavy acceleration, the computer
> ignores O2 sensor output and relies on input from other sensors to determine
> how much fuel to mix with the air.
>
> When the computer is using O2 sensor output, the system is referred to being
> in "closed loop" mode because it looks at O2 sensor readings to adjust the
> air-fuel mixture, then looks at the result of the mixture adjustment, then
> does the same thing over and over. The engine is operating most efficiently
> fuel-consusmption and emissions-wise when the system is in closed loop. In
> order to speed up the warmup process, the O2 sensors have heaters built in,
> and the automatic transmission will not shift into overdrive until the
> coolant temp is sufficiently warmed up.
>
> In all other operating conditions, the system is referred to as being in
> "open loop" because it is operating without O2 sensor input.
>[/color]
Ray,
How am I going to achieve "closed loop"?
by driving at lower speed without sudden speed up(I guess)? Thx.

<wenmang@yahoo.com> wrote in message
news:1158588878.883295.118680@h48g2000cwc.googlegroups.com...[color=blue][color=green]
> >[color=darkred]
>> > 2) what does it mean "Vehicle is in closed loop"?[/color]
>>
>> The O2 sensors only provide valid readings if A) the O2 sensor is
>> working,
>> B) the O2 sensor is warmed up, C) the vehicle is fully warmed up, and D)
>> the
>> engine is not operating at wide open throttle (WOT) or close to WOT.
>>
>> Since the O2 sensor only provides valid readings if all of the conditions
>> are met, for the conditions where all of those conditions are not met,
>> like
>> when the vehicle is first started or under heavy acceleration, the
>> computer
>> ignores O2 sensor output and relies on input from other sensors to
>> determine
>> how much fuel to mix with the air.
>>
>> When the computer is using O2 sensor output, the system is referred to
>> being
>> in "closed loop" mode because it looks at O2 sensor readings to adjust
>> the
>> air-fuel mixture, then looks at the result of the mixture adjustment,
>> then
>> does the same thing over and over. The engine is operating most
>> efficiently
>> fuel-consusmption and emissions-wise when the system is in closed loop.
>> In
>> order to speed up the warmup process, the O2 sensors have heaters built
>> in,
>> and the automatic transmission will not shift into overdrive until the
>> coolant temp is sufficiently warmed up.
>>
>> In all other operating conditions, the system is referred to as being in
>> "open loop" because it is operating without O2 sensor input.
>>[/color]
> Ray,
> How am I going to achieve "closed loop"?
> by driving at lower speed without sudden speed up(I guess)? Thx.
>[/color]

You are most likely to achieve closed loop with the engine fully warmed up
and driving at a steady speed above around 30 mph.
--

Ray O
(correct punctuation to reply)

Ray - update:
CAT monitor is finally done after I followed the instruction(for drive
cycle) obtained from Toyota techinfo.com. The P0420 disappeared and
didn't come back. Everyting is passed and no faulty code is stored. Why
is that? and what happened at first time(P0420 appeared and I had it
cancelled unaware that CAT is still under warranty)? Is CAT good or O2
sensor is marginal? Currently my 2001 Corolla has 5K miles shy from 80K
for CAT warranty, I may save money if the faulty code occurs before 80K
miles. What is your suggestion?

<wenmang@yahoo.com> wrote in message
news:1158894593.269253.238880@d34g2000cwd.googlegroups.com...[color=blue]
> Ray - update:
> CAT monitor is finally done after I followed the instruction(for drive
> cycle) obtained from Toyota techinfo.com. The P0420 disappeared and
> didn't come back. Everyting is passed and no faulty code is stored. Why
> is that? and what happened at first time(P0420 appeared and I had it
> cancelled unaware that CAT is still under warranty)? Is CAT good or O2
> sensor is marginal? Currently my 2001 Corolla has 5K miles shy from 80K
> for CAT warranty, I may save money if the faulty code occurs before 80K
> miles. What is your suggestion?
>[/color]

Wenmang, I am flattered that you sure seem to have a lot of trust in my
advice. So you and the other readers can evaluate the quality of the advice
I give, I'll let you know that I derive most of my advice based on a
combination of remembering something I read at some time, from a class I
took about 20 years ago, experience, and a basic understanding of how cars,
electricity, and simple machines work. I try to look at a problem at its
most basic level, remembering that an engine needs air, fuel, and a source
of ignition at the appropriate time; that E = I * R; and simple machines are
the wheel, lever, and inclined plane. If you remember that basic stuff and
realize that just about the entire car is based on those principles, you can
derive the solution to most car questions.

The P0420 trouble code probably cleared itself because it is one of the
codes with 2-trip detection logic. If the same fault is present over 2
drive cycles, the ECM will turn on the MIL (malfunction indicator light -
check engine light). Conversely, if the fault is not present over 2 drive
cycles, the ECM will cancel the code and extinguish the MIL. After you
cleared the codes and went through the drive cycles to get the ECM into the
ready state, the ECM probably has not detected the fault over 2 drive
cycles.

If you did not change the catalytic converter or O2 sensors, my guess is
that the same fault will appear again, hopefully, while it is still covered
by the emissions warranty. If it does appear, do not clear the codes. If
the car is still within the emissions warranty, take the car to a Toyota
dealer for repair. The O2 sensors are probably not covered by the emissions
warranty and the dealer will probably want to replace them, but they are a
lot less money than the CAT so IMO, it is a good deal. If you had the CAT
replaced, then the fault is probably cured.
--

Ray O
(correct punctuation to reply)

Thanks Ray. Every reader in this group may have idea who is expert and
who always provide sound advices to newbies like myself. The learning
curve may be too deep for me and I try to ask more stupid questions as
possible as I can. Please bear with me.
Sorry I didn't address my question clearly. I have two Corollas. 2000
Corolla has new CAT and 2 O2 sensors replaced and ready for State
inspection(due to bad CAT). My other Corolla(2001) had check-light
on(MIL was set) in July and faulty code is P0420 which is the same one
that my 2000 Corolla had/repaired for, and I had it cleared in July.
But since then CAT monitor has been stuck for my 2001 Corolla and about
2 months have passed, still the monitor cycle is not done. So, I
followed your advice and subscribed to Toyota techinfo.com and obtained
the procedure to run the drive cycle. Now, the CAT monitor is done but
no faulty code. That is reason why I was asking you why check-light
went on at the first place in July. If check-light was on and faulty
code was P0420 in July, now it disappears, what does it mean for the
same car?


Ray O wrote:[color=blue]
> <wenmang@yahoo.com> wrote in message
> news:1158894593.269253.238880@d34g2000cwd.googlegroups.com...[color=green]
> > Ray - update:
> > CAT monitor is finally done after I followed the instruction(for drive
> > cycle) obtained from Toyota techinfo.com. The P0420 disappeared and
> > didn't come back. Everyting is passed and no faulty code is stored. Why
> > is that? and what happened at first time(P0420 appeared and I had it
> > cancelled unaware that CAT is still under warranty)? Is CAT good or O2
> > sensor is marginal? Currently my 2001 Corolla has 5K miles shy from 80K
> > for CAT warranty, I may save money if the faulty code occurs before 80K
> > miles. What is your suggestion?
> >[/color]
>
> Wenmang, I am flattered that you sure seem to have a lot of trust in my
> advice. So you and the other readers can evaluate the quality of the advice
> I give, I'll let you know that I derive most of my advice based on a
> combination of remembering something I read at some time, from a class I
> took about 20 years ago, experience, and a basic understanding of how cars,
> electricity, and simple machines work. I try to look at a problem at its
> most basic level, remembering that an engine needs air, fuel, and a source
> of ignition at the appropriate time; that E = I * R; and simple machines are
> the wheel, lever, and inclined plane. If you remember that basic stuff and
> realize that just about the entire car is based on those principles, you can
> derive the solution to most car questions.
>
> The P0420 trouble code probably cleared itself because it is one of the
> codes with 2-trip detection logic. If the same fault is present over 2
> drive cycles, the ECM will turn on the MIL (malfunction indicator light -
> check engine light). Conversely, if the fault is not present over 2 drive
> cycles, the ECM will cancel the code and extinguish the MIL. After you
> cleared the codes and went through the drive cycles to get the ECM into the
> ready state, the ECM probably has not detected the fault over 2 drive
> cycles.
>
> If you did not change the catalytic converter or O2 sensors, my guess is
> that the same fault will appear again, hopefully, while it is still covered
> by the emissions warranty. If it does appear, do not clear the codes. If
> the car is still within the emissions warranty, take the car to a Toyota
> dealer for repair. The O2 sensors are probably not covered by the emissions
> warranty and the dealer will probably want to replace them, but they are a
> lot less money than the CAT so IMO, it is a good deal. If you had the CAT
> replaced, then the fault is probably cured.
> --
>
> Ray O
> (correct punctuation to reply)[/color]

[email]wenmang@yahoo.com[/email] wrote:[color=blue]
> Thanks Ray. Every reader in this group may have idea who is expert and
> who always provide sound advices to newbies like myself. The learning
> curve may be too deep for me and I try to ask more stupid questions as
> possible as I can. Please bear with me.
> Sorry I didn't address my question clearly. I have two Corollas. 2000
> Corolla has new CAT and 2 O2 sensors replaced and ready for State
> inspection(due to bad CAT). My other Corolla(2001) had check-light
> on(MIL was set) in July and faulty code is P0420 which is the same one
> that my 2000 Corolla had/repaired for, and I had it cleared in July.
> But since then CAT monitor has been stuck for my 2001 Corolla and about
> 2 months have passed, still the monitor cycle is not done. So, I
> followed your advice and subscribed to Toyota techinfo.com and obtained
> the procedure to run the drive cycle. Now, the CAT monitor is done but
> no faulty code. That is reason why I was asking you why check-light
> went on at the first place in July. If check-light was on and faulty
> code was P0420 in July, now it disappears, what does it mean for the
> same car?
>[/color]
I am wondering whether there was a false alarm for the first time when
check-light was on or some bad thing lying there is waiting to happen.

<wenmang@yahoo.com> wrote in message
news:1158928402.688874.131500@k70g2000cwa.googlegroups.com...[color=blue]
> Thanks Ray. Every reader in this group may have idea who is expert and
> who always provide sound advices to newbies like myself. The learning
> curve may be too deep for me and I try to ask more stupid questions as
> possible as I can. Please bear with me.
> Sorry I didn't address my question clearly. I have two Corollas. 2000
> Corolla has new CAT and 2 O2 sensors replaced and ready for State
> inspection(due to bad CAT). My other Corolla(2001) had check-light
> on(MIL was set) in July and faulty code is P0420 which is the same one
> that my 2000 Corolla had/repaired for, and I had it cleared in July.
> But since then CAT monitor has been stuck for my 2001 Corolla and about
> 2 months have passed, still the monitor cycle is not done. So, I
> followed your advice and subscribed to Toyota techinfo.com and obtained
> the procedure to run the drive cycle. Now, the CAT monitor is done but
> no faulty code. That is reason why I was asking you why check-light
> went on at the first place in July. If check-light was on and faulty
> code was P0420 in July, now it disappears, what does it mean for the
> same car?
>
>[/color]

OK, now your question makes a lot more sense.

For the 2001 Corolla, I cannot give you a definitive answer as to why DTC
P0420 cleared itself up and has not returned. Because of the 2-trip
detection logic, it is possible that the conditions have not appeared on 2
consecutive drive cycles, or perhaps the catalytic converter was beginning
to become coated with contaminants, and a trip on the highway burned off the
contaminants.

I believe that the trouble code will re-appear within the next 2 or 3
months, and if it does while the vehicle is still covered by the emissions
warranty, do not clear the code. Instead, take it to the dealership for
repair under the emissions warranty.
--

Ray O
(correct punctuation to reply)