im working on two cars with the same problem
one is a 1990 mits.eclipse the other is a 1991 ply.laser. both have the 2.0 duel over head cam. the problem is the hydrocarbon levels are to high around 200 at idle and at 2500 rpm.they also seem to have a miss at 2500 rpms. so ive changed the cats in both cars.checked the timing,checked for fuel pressure loss,checked the temp.sensor for the computer,replaced the spark plugs and wires,replaced the o2 sensor,and did a leakdown test on the compression.
Just take a deep breath and relax. Machine doesn’t lie, I’d bet you can find the cause.
BTW, when the last time you had your gas analyzer calibrated?
i thought of that so i put a couple of other cars on it and they read fine
Is this fuel injected? Leaky injector, maybe? High hydrocarbon level means too much fuel or not enough air.