[eleventeen]

I'm about to have to abandon my 2000 Toyota Avalon v6 3.0 (all Avalons have this and only this engine) with 78K miles because I can't get rid of a diagnostic "Cat not ready" message. Everything else passes fine. Car runs fine, rather better after changing the sensors. If I can't pass CA smog, I can't register the car and thus can't legally drive it.

I have: changed both upstream 02 sensors. Changed downstream post-CAT) sensor. I have gone through the following reco'ed drive cycle.

1. Make Sure the Engine Light is Off 2. Check if your Vehicle has a Coolant Temperature The drive cycle starts with a cold start. 3. Let the Engine be Idle for 2 Minutes The next step is to start the engine and keep it idle for two and half minutes, keeping >>rear defroster and AC on.<< 4. Drive the vehicle at a Steady Speed of 55 MPH Now, switch the rear defroster and ac off and keep the speed of your vehicle at 90 km/hr (55MPH) nearly for 3 minutes. During this period, the purge and Fuel monitor diagnostics will take place. 5. Decelerate your Vehicle’s Speed at 20 MPH Make the speed of your vehicle fall gradually up to 32 km/hr (20 MPH). Avoid touching/shifting of clutch or brake. 6. Again Speed Up Drive your vehicle back to 55MPH (90 km/hr) at 3/4 throttle for nearly five minutes. The catalyst monitor diagnostics will take place during this period. If the battery is detached or the catalyst is not ready, it might take five complete driving cycles to decide the status of the catalyst. 7. Stop the Vehicle Now, make your vehicle slow down and allow it to sit idle for 2 minutes.
Have done all of this. I have researched the drive cycle (and there are about four different versions all over the 'net) and done most of them several times.

Really at the end of my frickin rope and driving around with the pass seat taken out and passenger side trim all apart.

Anyone? Yeah, I know it's a *#&^$%@ 20 year old car. With 78K miles.

I'm thinking I have to to go to a real repair shop and have them monitor actual OBDII voltages with the idea that even though the sensors have all been replaced, something or other is acting flaky and the CAT monitoring whatever (I have only a cheapo OBDII scanner) is simply not learning the CAT behavior right.

 

[Desertds]

Have you cleared the cel to see if it comes back?

 

[eleventeen]

Have you cleared the cel to see if it comes back?

I'm not sure what you mean by "cleared the cel". The "cat not ready" message NEVER WENT AWAY. ALL my numerical codes are gone.

 

[BMR]

What brand of O2 sensors were installed? Preferably Denso or OEM. Others, notably Bosch, don’t play well with Toyotas. Also, if Densos, where did you buy them? There are a lot of counterfeits out there that are garbage, especially on eBay and even Amazon.

“Cleared the cel” = cleared the Check Engine Light. Which is not applicable in your case, as you’re dealing with a system not ready problem, as opposed to a code being thrown by the ECU. These can be really stubborn about going to “ready”, as you’re experiencing.

 

[eleventeen]

What brand of O2 sensors were installed? Preferably Denso or OEM. Others, notably Bosch, don’t play well with Toyotas. Also, if Densos, where did you buy them? There are a lot of counterfeits out there that are garbage, especially on eBay and even Amazon.

“Cleared the cel” = cleared the Check Engine Light. Which is not applicable in your case, as you’re dealing with a system not ready problem, as opposed to a code being thrown by the ECU. These can be really stubborn about going to “ready”, as you’re experiencing.

Apologies, "cel" obvious abbrev did not register. Yeah, aftermarket (Not Bosch) but not marked Denso sensors. *#&^@%@#

 

[Bigplanz]

Do a google search for this Toyota TSB if you don't already have it. I found a PDF of it. All the 411 on Toyota drive cycles. You can sell the car here in Kentucky; no emissions testing here.

Toyota TSB EG003-02.

 

[[email protected]]

My biggest hurdle with that monitor used to be coolant temp. If it doesn’t reach at least 178 degrees the monitor doesn’t run, a piece of cardboard in front of radiator can help, as opposed to replacing the thermostat. Sometimes while driving at highway speeds, especially in the winter, the temp will drop and the catalyst monitor won’t run. If both your O2 and O2 heater monitors have run, try the cardboard trick, take a 20 mile
Highway drive, maintain constant 60 mph and watch the temp gauge and make sure it doesn’t overheat also.

 

[[email protected]]

Another thing you could try is disconnecting both battery cables and holding them together, this will remove all keep alive memory from the PCM, I’ve heard other manufacturers with troublesome monitors and drive cycles have had success doing that as well. I’d say for about 5 minutes to be sure of all memory erasure. Make sure both cables are disconnected from the battery before attempting!

 

[[email protected]]

Of course that will clear, make all monitors go to incomplete/not ready. You’ll then start fresh with a drive cycle.

 

[Mr. Biggles]

The trick in this video works for Catalyst Readiness:

Basically:
1) In park, warmup your car to operating temperature for 5-10 minutes.
2) While still in park, slowly rev your engine to around 3000 rpms.
3) Keep the rpms steady there, or a little above, for 3 minutes.
4) Slowly release your foot off the gas until you're just idling.
5) Heated Catalyst Readiness should be set afterwards.

Not sure if it will work you, but it worked for my gf's 2002 Toyota Avalon 3.0L V6 yesterday. I sat in the the car with her, timed her while she did it, and monitored her Catalyst Readiness with my scan tool, before and after she completed the procedure.

 

[eleventeen]

The trick in this video works for Catalyst Readiness:

Basically:
1) In park, warmup your car to operating temperature for 5-10 minutes.
2) While still in park, slowly rev your engine to around 3000 rpms.
3) Keep the rpms steady there, or a little above, for 3 minutes.
4) Slowly release your foot off the gas until you're just idling.
5) Heated Catalyst Readiness should be set afterwards.

Not sure if it will work you, but it worked for my gf's 2002 Toyota Avalon 3.0L V6 yesterday. I sat in the the car with her, timed her while she did it, and monitored her Catalyst Readiness with my scan tool, before and after she completed the procedure.

I tried that, twice. But thanks, I do appreciate it! I am strongly leaning towards a counterfeit or bad-out-of-the-box downstream (eg; CAT) sensor at this juncture. Yes, I bot my 3 qty sensors off ebay. The upstream sensors looked "plausible". Judging by the metal color on the body of the sensor. Which is silly, I know. The CAT sensor I bought from another source. Looks different. Different metal color (shinier, not that bronzish metal color of the two apparently functioning upstream sensors, like the ones I pulled out.) Not a blue and white wire [plus the two black wires] ....instead, two white wires. Now; does the color of the wires mean anything in terms of what voltage travels over those wires? No. Does the color of the metal on the body of the sensor matter? No. But the *#&$^$%@# doesn't work.

 

[Vangm25]

Denso ONLY, don't buy from eBay or Amazon as there can be counterfeits.

2000 TOYOTA AVALON 3.0L V6 Oxygen (O2) Sensor | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

To properly heat up the catalytic converter, all you gotta do is go on a nice long drive. No need for any procedure because the only time the catalytic converter is gonna warm up is when the engine is ON. In other words, go on a nice drive. No need for any procedure as just going on a nice drive will do the same thing.

 

[eleventeen]

Denso ONLY, don't buy from eBay or Amazon as there can be counterfeits.

2000 TOYOTA AVALON 3.0L V6 Oxygen (O2) Sensor | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

To properly heat up the catalytic converter, all you gotta do is go on a nice long drive. No need for any procedure because the only time the catalytic converter is gonna warm up is when the engine is ON. In other words, go on a nice drive. No need for any procedure as just going on a nice drive will do the same thing.

I just ordered a Denso from Rock. Gotta get this handled. Thanks for that referral!

 

[eleventeen]

Denso ONLY, don't buy from eBay or Amazon as there can be counterfeits.

2000 TOYOTA AVALON 3.0L V6 Oxygen (O2) Sensor | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

To properly heat up the catalytic converter, all you gotta do is go on a nice long drive. No need for any procedure because the only time the catalytic converter is gonna warm up is when the engine is ON. In other words, go on a nice drive. No need for any procedure as just going on a nice drive will do the same thing.

OH PRELIMINARY GLORY BE!
Replaced ebay CAT sensor with genuine Denso CAT sensor from ROCK, Completed drive cycle.
NOW my CAT sensor reads "N/A"
It does NOT read "READY"
OTHER readiness sensors read either "READY" or N/A
THIS IS AT LEAST A CHANGE! AT LEAST IT IS NOT READING "NOT READY"!
[full excitement]
Gonna drive around a few more days and see if I can achieve a READY for Mr. CAT.
Strongly thining this was a matter of the genuine Denso sensor in the downstream position.
Vang! Owe you a beer! perhaps an Asahi! Many thanks!