Trouble with Emissions!

dcs7941 · Dec 29, 2009

I failed emissions test today and ran a test for trouble codes and came up with the following:

KOEO (Key ON, Engine Off):

Code #327 - EGR Valve Position (EVP) sensor signal voltage too low.

Will replacing the EGR Sensor solve this problem?

Thanks,
dcs7941

HISSIN50 · Dec 29, 2009

Check the sensor's connector for in/out voltage (KOEO). Let us know what that voltage is.

Did you make sure the connector is plugged in? It is easy to leave off accidentally.

dcs7941 · Dec 29, 2009

Hi HISSIN50

There are 3 prongs in the connector. Which one should have the voltage?

HISSIN50 · Dec 29, 2009

dcs7941 said:
Hi HISSIN50

There are 3 prongs in the connector. Which one should have the voltage?

Brown and white will have 5V.
Brwn/lt grn should show about 0.60V with the key on or with the car idling.

dcs7941 · Dec 29, 2009

HISSIN50

Here is what I found:

Brown/White Wire has a voltage of 4.98V
Brown/Light Green Wire has a voltage of 0V (Maybe the problem)
Gray/Red Wire I assume is negative or ground

Let me know what you think could be the problem.

Thanks,
dcs7941

HISSIN50 · Dec 29, 2009

It's is likely that either the sensor is bad, or the interface between the position sensor and EGR valve is out of whack (it happens when the EGR seat wears).

You can do some testing with the position sensor if you want, or you can replace it and hope that's the solution. I'd tinker with it first (KOEO, manually open the EGR valve with a vacuum pump and see if the Brown/lt grn starts showing voltage).

Sometimes you can modify the sensor to accomodate the wear.

dcs7941 · Dec 30, 2009

I performed the test wrong the first time. I plugged the connector into the EGR Position Sensor and probed the wires with my digital volt meter. Here are the results:

Brown/White Wire has a voltage of 4.98V
Brown/Light Green Wire has a voltage of .50V (KOEO)
Gray/Red Wire I assume is negative or ground

I did purchase a EGR Position Sensor so maybe I will give it a try.

Thanks,
dcs7941

HISSIN50 · Dec 30, 2009

If you open the EGR valve, does that 0.50V value increase?

dcs7941 · Jan 1, 2010

I replaced the EGR Valve Position Sensor and drove the car for about 10 miles. I did a code reader test and it seems the problem has been fixed. I will drive it some more and do another test to make sure before getting another emissions test. Thanks HISSIN50 for all the help.

dcs7941

dcs7941 · Jan 9, 2010

I took the car for a retest and it passed but just barely.

NOx ppm
Reading=816
Allowed=821

Would a tune up help in getting the NOx level down?

Thanks,
dcs7941

HISSIN50 · Jan 10, 2010

An EGR tune-up might help. Make sure the electical and vacuum side of things are good and make sure there are no obstructions in the EGR passageways.

dcs7941 · Dec 28, 2010

I just got an emissions test done today and this year my car failed again. Here are my results:

25/25 Test
NOx ppm Reading 965 Allowed 821

I have new plugs, wires, ignition distributor and all emissions equipment on the car. What would help me get this thing passed?

HISSIN50 · Dec 28, 2010

How did the EGR components and passages look?

WhiteCobra95 · Dec 28, 2010

Where is your base ignition timing set? If it's at 14 or 16 deg, retard it to 10 or 8 degrees and try again. If that's not it, it's probably EGR related. The combustion relationship of nox is P*T^4 in the chamber during combustion, so anything you can do to cool the combustion process will reduce NOx (i.e. late spark timing or EGR flow).

Good luck!

dcs7941 · Dec 28, 2010

I will check the timing and adjust to 10 degrees and also test the EGR Valve. I will let you guys know if this helps the emissions. Thanks!

revhead347 · Dec 28, 2010

I'd just go ahead and replace the EGR valve. Those things get full of crap after awhile and don't work so hot.

Kurt

dcs7941 · Jan 1, 2011

You guys were correct on this issue. I purchased a vacuum pump and tested the EGR Valve. I applied 10 inches of vacuum and the EGR Valve did not hold the vacuum steady at all. I replaced the valve and drove the car for about 30 miles before I had it retested. Passed!!!! Thanks for your help.

dcs7941 · Dec 5, 2011

Although I haven't taken my emissions test for 2011, I just replaced the PCV Valve along with new hoses. My car has 271,000 miles and I never knew that there was a Crankcase Filter sitting below the PCV Valve that also needs to be replaced. This may have been a part of my problem with emissions. I installed a new one and will let you guys know how my test turns out next week. Removal is easy once you get the grommet and valve removed. I used a pick set from Autozone and it pulled out with ease. See photos of a 271,000 mile filter compared to a new one.

dcs7941 · Jan 19, 2012

dcs7941 said:
Although I haven't taken my emissions test for 2011, I just replaced the PCV Valve along with new hoses. My car has 271,000 miles and I never knew that there was a Crankcase Filter sitting below the PCV Valve that also needs to be replaced. This may have been a part of my problem with emissions. I installed a new one and will let you guys know how my test turns out next week. Removal is easy once you get the grommet and valve removed. I used a pick set from Autozone and it pulled out with ease. See photos of a 271,000 mile filter compared to a new one.

Update on 2011 Emmision Test. Failed the Nox test. Replaced the Bassani X-Pipe with Cats with a new one and now the car is fine. It was the catalytic converters the whole time.

revhead347 · Jan 20, 2012

You can take that breather filter out real easy with a magnet too. Good cats go a long way.

Kurt

Trouble with Emissions!

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