help with emissions

[xt32]

hey guys, the car is a 91 turbo with a full cat back and down pipe, with stock cat with about 90k on it. here are the results:

standard reading
NOx 853 116
HC 114 325
CO% .63 3.74

What do you think the results suggest as a possible problem? Any common things to check for or replace that might help?

thanks.

 

[T34418L3ONE]

rich misfire, check your FPR or and your spark plugs

 

[jetjock]

It's rich alright. Check what T344 said. If it's been like that for awhile it hasn't been doing your cat any good either. Any codes? Is the engine running in closed loop? O2 sensor cross counting? Airfilter and induction system clear?

 

[mrnickleye]

Well...at my smog repair shop we diagnose for $75. Get it out here, and I'll have it done for $50.
Seriously...it might be worth having it diag'd. You can change the 02, and repair some other things yourself.
A cat installed here is $150.

Most EGR systems on our cars have plugged passages by now. You can clean them.

You can do plugs, wires, etc.:biglaugh: