It's a 1993 super coupe, the car has 200,000 miles on it, the engine and transmission was rebuilt in the past 50,000 miles and the car has been well taken care of. I've been trying to troubleshoot this knock recently and I take it to get smogged and the NO emissions are high, around 700 ppm. I've done the KOEO test and it didn't pull any codes, I did the KOER test a few times and once it registered some weird numbers like 6225 and 67225, but the rest of the time it registered okay.
I'm thinking it could be the MAF, O2 sensors, or knock sensor. It knocks when under medium to heavy acceleration, particularly when going up hills. I've tried putting some of the engine cleaner in it and then used a full tank of gas and the knock is still there, as are the high NO readings.
Any sort of ideas on how to know exactly which sensor might be bad or any other causes for this knock?
I'm thinking it could be the MAF, O2 sensors, or knock sensor. It knocks when under medium to heavy acceleration, particularly when going up hills. I've tried putting some of the engine cleaner in it and then used a full tank of gas and the knock is still there, as are the high NO readings.
Any sort of ideas on how to know exactly which sensor might be bad or any other causes for this knock?