I have a 1988 Integra with about 150k miles. In between fillups on a
road trip this year the car was all of a sudden running rough at
idle. And, it stumbles slightly during initial acceleration. I also
noticed at least a 15% reduction in highway fuel economy, though at
highway speed the car still runs fairly smooth. All cylinders are
The engine light occasionally comes on now for a few seconds then back
off, usually at idle. Idle speed is normal, and I've actually
adjusted it up due to the rough idle. Since the trip I have replaced
the plugs, cap, rotor, and air filter. I have since checked the ECU
and it indicates code #1 (oxygen sensor). Now, what exactly is this
telling me about the sensor? Is it possible to get this code due to
other conditions if the sensor is in fact still good?
When changing the plugs I noticed that number 3 was unusually black
(carbon). After a couple weeks with the new plugs, number 3 is again
blacker than the others but still firing fine.
I've reset the ECU and waiting for the next occurence. Should I just
replace the oxygen sensor? Any other ideas?