Hi guys,

I came up with NOx readings in the range of 1200-2300 on my 15mph/25mph tests, respectively... failed needless to say.

Anyone else have this problem? CO2 are near optimum, O2 are slightly high. HC near Max. CO are OK...

I'm thinking bad EGR system or high carbon buildup in C chamber leading to high temperatures that leads to the high NOx.

I have been driving a whole 1 mile to/from work each day then shutting off the engine before it's warmed up... for the last 4 years... do you think that's enough to clog any systems? NE1 else experience this?

TIA

 

Do you get incredibly poor gas milage? I don't know much about emmissions because us New Zealanders dont care for emmissions in our clean green country, but I do know that your car will be running in open loop mode for most of its life. This is where the O2 sensors are not giving a reading till they heat up, so the ecu is running a very rich mixture to heat the car up quickly. I guess this would cause carbon buildup because the car won't have had enough chance to burn it off.

PS: you didn't drive a mile to get it tested did you?

 

Nah, the engine was well warmed up... And I recently (6months ago?) put 2 new O2 sensors in. The high NOx usually indicates temperatures that are TOO HIGH during the combustion.

 

Did you figure this out? I am having some of the same issues.

SuDZ

 

Bump!!!!!!!!!!!!!!!!!

 

EGR is likely. I found this pretty helpful. http://www.car-sound.com/04charts.asp

Try to seafoam it a few times and then if that doesn't work replace the EGR pipes and clean the valve.

 

hmm... 1mile to/from work. Is that even worth the gas your spending?