968Forums.com

Hi folks,

 

I have a 1993 968 that just failed an emission test due to high NOx levels.  First time it has ever failed!  Anyway, after some online searching, I see that a bad O2 sensor could be the cause.  I checked my records and see that it has been at least 10 years since I replaced it, so that is job #1.

 

I also see that a bad/dirty EGR valve can cause high NOx as well.

 

1.  Does this car have an EGR valve?  If not, is there something similar, perhaps with a different name?

2.  Where is this part located?

3.  Anybody take theirs apart, clean it, etc.?  Any guidance would be appreciated.

4.  A part number would be great, if replacement is better than cleaning.

 

Forgive me in advance if this has already been posted; I used the search function and couldn't find anything.

 

Thanks!

there is no EGR valve.

 

do you have the OEM cat in there?

what chip are you running?

Thanks flash!  I have a replacement cat (only 2 years old), no chip.

 

Hopefully the O2 sensor fixes things.  All of the other numbers (HC, CO) are perfect as usual.

Do a blink test to check the codes. There should be a code if the O2 sensor is bad. You can do a search on site for the codes and how get your car to do the blink test.

Thanks Ryan.  Just did a blink check, no codes (just the "all clear" 1-5)...  maybe the O2 sensor is electrically fine, but dirty as hell?  Anyway, it's a pretty cheap fix (bought a generic $18 sensor on ebay and I have a cheap mechanic that will install for $50), I'll post back after I do it and get the car retested.

regardless of what the catalogs say about working on the 968, unfortunately the aftermarket cats do not generally work.  they are cleared only for the size and number of cylinders, and not on any specific engine.  i have seen quite a few of them fail.  in fact, in order to get the biggest one i could find to work, i had to get it REALLY hot.

Check for vacuumleaks. Because a very lean mixture have a much higher nox emission as a result..

and another hidden item in our cars is the charcoal canister which is located in the front wheel well drivers side.