Hello,
I am having a major problem getting my non turbo 97 Volvo 850 to pass smog. The NO levels about a couple months ago were around 200 points too high (around 700) at 15 mph test. Without doing any repairs I took it back in and the NO levels are pushing around 1400 now. My smog is due in about a month and I would really like to get this figured out. If anyone has any suggestions on what is most likely the problem I would be happy for the help. Thank You!

 

first thing I would do is take it to an auto parts store and have them scan for codes, I would bet an O2 sensor is out.

 

@#%$^

 

Hey thank you for the help guys. Ya the car is running lean that much I know of. I have a code reader so I am able to follow the codes that pop, but I have had two codes come up and they were both different each time (for some reason my computer takes a veryyyy long time to cycle through everything). I took a look and all wires and hoses look to be fine. The two codes that have popped have been secondary air system, which hasnt come on again, and the latest one was mass air sensor. I am guessing from what I have looked up it seems like a bad O2 or Cat problem.

 

I'd check that the SAS valve is operating. If it's stuck open, could engine management issues, as well as ruining your air pump ($$$).

Also did you at least clean the MAF, being that it threw a CEL?

 

Just a note: I have been reading a lot about BURNT VALVES. One of the main causes is running lean. Try to get that figured out and fixed asap.

 

Also, are you running 91+ octane? These cars are designed to run on 91. That may be 1/2 your problem.