I recently had an emissions test performed on my 97 Avenger ES (2.5L) and it failed due to high NO (466 ppm, limit 435 ppm, at 40 km/h). Using my trusty OBDII code reader I found that an O2 sensor is malfunctioning (code P0135: O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)).

I've read of various reasons as to why high NO could be present. Would this be the most likely reason? Also, from what I can tell from the manuals, there are two O2 sensors, one on the manifold closer to the driver and one somewhere after the manifold. Is the one on the manifold my bad one (bank 1 sensor 1)?

FYI, my other test numbers were:

@ 40 km/h
HC = 20 ppm (limit = 58 ppm); CO% = 0% (limit = 0.32%); RPM = 1918; Dilution = 15.00

@ idle
HC = 17 ppm (limit = 200 ppm); CO% = 0% (limit = 1%); NO = N/A (either this test isn't performed at idle or they didn't do it because it failed the 40 km/h test); RPM = 760; Dilution = 15.1

Thanks for any help/advice.

 

yes the o2 can cause it and the bank 1 one is the drivers top , you can swap and see if it clears it can be a proken wire as well (no voltage to heater)

 

Hi'

Bank 1 - sensor 1
This is the sensor between the engine & firewall - upper one in the exhaust manifold. You can get it out if you use a sensor 'socket' or you have to remove the UPPER INTAKE (Plennum) - fairly easy task.

Also you have 4 sensors total

 

Thanks guys. I thought I picked the correct sensor in question. I've read five or six things, including two manuals, and they are all inconsistent with each other. I did find this little guide (can I post this here? http://www.justanswer.com/dodge/2c8c...same-code.html).

If you ask me you shouldn't have to have an emissions test/do any related work on the car unless it's spewing out black crap. Also, I drive about 8,000 km a year, yet someone who drives 40k+ has to abide by the same standards as me. This emissions test is a scam I tell ya! (end of rant).

 

Hello!

After replacing the O2 sensor my car once again failed the test. The NOx was even higher this time, and this time the test was done when the engine was hot (30 minute city driving; last time the car had be driven for about 2 minutes and then sat in the parking lot for 15 minutes).

I am thinking that perhaps the EGR valve may be dirty, however, I`m also wondering what the EGR pipe does. It extends from the exhaust manifold to the intake manifold, but it doesn`t appear to be connected to the EGR valve in any way.

Should I bother taking the pipe out and cleaning inside of it or would the problem more likely be with the valve itself?

Thanks.

 

you can block it off and see if it passes , two bolts on rear of manifold make a plate out of metal

 

I took apart the valve/transducer, cleaned it all up and tested it and it seemed to work fine. How does blocking off the valve help?

A friend of mine has an R32 which does not have an EGR system and he sometimes has trouble passing due to high NOx. He said that he adds methanol to the gas tank in a 4:1 gas to meth ratio and this helps him pass. If I can't find anyone to "help" with this e-test I may try that.

Also, I have a minor knock in the engine, and after reading possible causes for high NOx I'm wondering if a timing issue could be the case.

 

i can not find the camshaft positioning sensor in my 98 avenger ive looked for two days with no luck at all

 

What Motor ?