Advice Request - Emissions Failed

[GTA_Guy]

Hi
I have a 98 Camry 2.2 that failed emissions test 2 years ago. The o2 sensor was replaced which helped but didn't cure the issue. Sorry if this is information overload but below are historical emissions tests. I'm planning to clean the throttle body and remove, check and clean the EGR Valve. What are the chances this will help? Anything else that I can do to prepare? What is Dilution?

Thanks in advance.

2007
40 k/h @ RPM 1846, Dilution 14.69
HC ppm 17 pass
CO % 0.09 pass
NO ppm 8 pass

IDLE @ RPM 711, Dilution 14.50

HC ppm 12 pass
CO % 0.00 pass
NO ppm na pass
==========
2009
40 k/h @ RPM 1887, Dilution 15.11
HC ppm 52 pass
CO % 0.73 fail
NO ppm 545 fail

IDLE @ RPM 708, Dilution 14.64

HC ppm 31 pass
CO % 0.04 pass
NO ppm na pass
==========
2009 after O2 sensor changed (RPM higher for both tests)

40 k/h @ RPM 1869, Dilution 15.00
HC ppm 24 pass went down
CO % 0.21 pass went down
NO ppm 564 fail went up?

IDLE @ RPM 722, Dilution 14.70
HC ppm 20 pass went down
CO % 0.00 pass went down
NO ppm na pass

[Mister_Perkins]

• leaks, holes or disconnected components in the engine's exhaust system
• engine idle speeds set below the manufacturers' specifications
• large exhaust systems that are bigger than what the vehicle normally requires
• misfiring cylinders including lack of spark; incorrect air/fuel mixture
• mechanical engine problems such as worn rings, deficient valve operation, defective valves, loose cylinder head bolts or a blown head gasket
  
  The above are causes of dilution.
  
  What is Dilution?

The emissions testing equipment automatically determines if exhaust gases are being diluted before and during every test. It does this by verifying that enough combustion byproduct, carbon dioxide (CO2), is present in the exhaust gases. If there is not enough CO2 present, the computer will not allow the test to proceed and the vehicle will be rejected.


exerpts Taken from :
http://www.ctemissions.com/expect-dilution.html

[96ToyoCam164K]

Or you could just move to Florida, they got rid of emissions testing back in the 90s

[Mister_Perkins]

More than likely I would say you probably have a hole or leak in ur exhaust somewhere. Push your hand over the end of the muffler tightly and listen. if you hear PSSSSSHHHHHHHHHH anywhere, thats the problem

[GTA_Guy]

Thanks for the info on Dilution. The readings then were 'in range' but I have a small leak in the muffler that may mess me up this time around.

What about the high NO ppm beyond cleaning Throttle boday and EGR valve?

BTW the CEL has been on since I bought the car, my mechanic wasn't too concerned and said that since it runs well and he didn't know for sure the issue, I'd have to throw money at it till they changed the right part. I wish I had a scan tool so see if it was always throwing the same code etc.

Thanks

[Hajoca]

Where in GTA are you??

Which CEL codes do you have?

[JohnGD]

High NO is to check the EGR system. Besides cleaning the pipe and valve that may carbon up, also check the VSV that turns on the EGR valve.

Clean the IAC by disassembling it. The carbon on the back of the rotor is hard to clean out otherwise.

5sfe IAC Removal (lots of pictures)

Originally Posted by GTA_Guy

What about the high NO ppm beyond cleaning Throttle boday and EGR valve?

BTW the CEL has been on since I bought the car, my mechanic wasn't too concerned and said that since it runs well and he didn't know for sure the issue, I'd have to throw money at it till they changed the right part. I wish I had a scan tool so see if it was always throwing the same code etc.

Thanks

[fenixus]

The fastest way to fix EGR problems is to replace the forsaken EGR trio, The valve, modulator and VSV, all 3 OEM from online dealer around $250 in parts, you will also get a newer revised (black top) design of EGR Valve one thing order new gaskets (2) for it and get new mounting bolts to exhaust pipe.
also make sure the hoses do not slowly leak vacuum (it rarely gives a code) and are not blocked (that would give you a code P0401 likely).

one last thing to check per EGR VSV is to make sure the electrical ground it uses is clean and tight. it's located on the back of intake runners, behind the one for cylinder #1 (passenger side). mine was dirty with oil leaking from bad VC gasket above and caused some intermittent problems with VSV not actuating always when needed to.
I also replaced all EGR components as all of them were somewhat off the spec and the valve didn't survive cleaning unfortunately.

[fenixus]

oh, and there are also some Emissions Formula cleaners, the strongest fuel additive (still safe though) they sell is called CRC Emissions Formula, around $10 in Autozone. if all fails this could help. one thing do NOT drive to emissions station with this additive in tank, because they fail you. you need to run a tank of gas with it and then refill fresh fuel.

as suggested above by John, also try thoroughly cleaning the IAC, get new TB gasket and IAC gasket before you start. lots of PB Blaster and good grip screw driver (Philips #2) or screw driver bits on 1/4'' ratchet may come handy.

[GTA_Guy]

I've done a fair bit of work in the last while, with 206K on it, it seemed like time. I've replaced (using dealer items) all 4 Sway Bar Links (left front was broken, right front came apart in my hand), RSB bushings, fuel filter, pvc, pvc hose and grommet. I also had a little oil on the insulator of first plug on the driver side (#4?) so I replaced the spark plug tube seals as well.
While apart I thought I'd check the valve clearances. Not sure if I did this 100% right, but for each set of valves I measured using the biggest feeler gauge in my set that would fit when the cam lobe was at the top, wroted it down, turned the crank with a ratchet and repeated for the next set etc. Most are in spec I think;
Intakes:
Pass Side Driver Side
.178/.203 .178/.229 .254/.229 .203/.203
Exhaust:
.305/.330 .330/.330 .305/.330 .279/.279

Also did a compression test, all readings were in the range of 210 - 220.
I've also removed and cleaned (with Sea Foam) the Throttle body, fuel rail, egr, egr modulator, associated pipes and replaced all associated gaskets. I couldn't unscrew the 4 IAC screws and didn't want to drill them out, so cleaned it as well as possible while the throttle body was off the car without taking it apart. I've also disconnected / reconnected most sensor contacts and sprayed with electrical cleaner.
Recently I ran some fuel system cleaner (CRC Emissions Formula) through a tank. I also purchased a scanner. My codes were
P0120 P0420 and P0446. I've since cleared the codes and waiting to complete a complete drive cycle.

Thanks to EVERYONE on these forums for the tips, adivce and taking the time to make excellent DIY's.

[SilverSoarer]

Drive the car for at least 30 mins before taking it in for emissions.

If you take the car in on a rainy day, it will lower your NO count by 30%.

[fenixus]

wow, a lot of work you performed!

If you plan on keeping the car for long I would also think of replacing the upstream oxygen sensor (or AFR sensor on Calif specs) which is used by ECU for fuel trim adjustment, and also replace the downstream/rear oxygen sensor (under car) which is used for cat converter monitoring.

P0120 - Throttle Pedal Sensor Switch "A" Circuit.
(have you by any chance unplugged the TPS while car was running or ignition turned to ON position? if yes then safe to ignore likely)

P0420 - Catalyst System Efficiency below Threshold.
(replace downstream o2 sensor first before anything)

P0446 - EVAP Control System Vent Control.
(first get a new OEM fuel tank gas cap from dealer and go from here).

[JohnGD]

The intake below 0.19 and the exhaust below 0.28 are on the tight side. You will need to retorque the spark plug tube nuts after a couple of weeks as the grommets can take a set.

If you changed only the upstream oxygen sensor then change out the downstream one too. Loosen and tighten the gas cap. Clear the codes and see if they come back.

Verify the operation of the EGR valve by plugging in a MityVac into the vacuum hose off the valve itself. See what readings you get from idle to 2500 rpms on a warm engine.

When was the last timing belt and spark plug change on this car?

Originally Posted by GTA_Guy

Intakes:
Pass Side Driver Side
.178/.203 .178/.229 .254/.229 .203/.203
Exhaust:
.305/.330 .330/.330 .305/.330 .279/.279

[GTA_Guy]

My check engine light is back but the good news (I think) is that I'm only seeing P0446 at this time and there are no pending codes. I'll replace the gas cap this week - I do always turn till it clicks about 6 times so hopefully it's just a defective cap.

About the valve clearences, is this something I should worry about? The timing belt was changed at about 160,000k about 50,000k ago. Spark plugs were cleaned and gap checked April this year. It runs ok so I'm assuming the wires are ok.

Below are Oxygen Sensor tests done by the tool, and a 'Freeze frame' for the P0446 code. The link below is also spreadsheet and graphs of live data collected from the scan tool. Any comments / recommended resources on intepreting the scan info would be great, the tool doesn't come with much in that respect.

Oxygen Sensor Monitor Bank1 - Sensor 1
$03 Low sensor voltage for switch time calculation .4v
$04 High sensor voltage for switch time calculation .55v
$07 Minimum sensor voltage for test cycle 1.275v
$08 Maximum sensor voltage for test cycle 0.0v
Oxygen Sensor Monitor Bank1 - Sensor 2
$07 Minimum sensor voltage for test cycle 1.275
$08 Maximum sensor voltage for test cycle 0.0v

Freeze Frame Data for P0446
Fuel CL
Calculated Load 36.47%
Engine Coolant Temp 91 deg C
STFT - Bank 1 -3.13%
LTFT - Bank 1 4.69 %
Intake Manifold Absolute Pressure 37 kPa
Engine RPM 599
Vehicle Speed Sensor 0
Intake Air Temp 26 deg C


http://www.flickr.com/photos/gta_pho...in/photostream

http://www.flickr.com/photos/gta_pho...n/photostream/

Thanks again

[sam333]

Originally Posted by GTA_Guy

My check engine light is back but the good news (I think) is that I'm only seeing P0446 at this time and there are no pending codes. I'll replace the gas cap this week - I do always turn till it clicks about 6 times so hopefully it's just a defective cap.

About the valve clearences, is this something I should worry about? The timing belt was changed at about 160,000k about 50,000k ago. Spark plugs were cleaned and gap checked April this year. It runs ok so I'm assuming the wires are ok.

Below are Oxygen Sensor tests done by the tool, and a 'Freeze frame' for the P0446 code. The link below is also spreadsheet and graphs of live data collected from the scan tool. Any comments / recommended resources on intepreting the scan info would be great, the tool doesn't come with much in that respect.

Oxygen Sensor Monitor Bank1 - Sensor 1
$03 Low sensor voltage for switch time calculation .4v
$04 High sensor voltage for switch time calculation .55v
$07 Minimum sensor voltage for test cycle 1.275v
$08 Maximum sensor voltage for test cycle 0.0v
Oxygen Sensor Monitor Bank1 - Sensor 2
$07 Minimum sensor voltage for test cycle 1.275
$08 Maximum sensor voltage for test cycle 0.0v

Freeze Frame Data for P0446
Fuel CL
Calculated Load 36.47%
Engine Coolant Temp 91 deg C
STFT - Bank 1 -3.13%
LTFT - Bank 1 4.69 %
Intake Manifold Absolute Pressure 37 kPa
Engine RPM 599
Vehicle Speed Sensor 0
Intake Air Temp 26 deg C


http://www.flickr.com/photos/gta_pho...in/photostream

http://www.flickr.com/photos/gta_pho...n/photostream/

Thanks again

What type of scan tool do you have?