1998 Honda Civic 4 cyl Front Wheel Drive Manual 104800 miles
I have a 1998 Honda Civic CX with approximately 104,800 miles. The car has experienced only usual mechanical wear throughout its life - no accidents or other problems. The exhaust from the cat converter down was replaced at 98000 miles with no problems -old O2 sensors were reused. I recently had the clutch replaced as routine maintenance. Almost immediately after getting the car back it put out a DTC code of P0133. I checked all of the wiring and everything seems to be in order. Simple voltmeter test indicates that the oxygen sensor is working properly. Based on the age of the car and the mileage, I went ahead and replaced the oxygen sensor before (actually at the top of the cat conv - there is another after) the converter anyway (Bosch replacement part). Car seems to be running very smooth, yet the code returns again after a few trips (idled fine for over 30 minutes without generating a fault - then drove it several miles with no problems, after several trips same DTC returns). I have checked wiring and the engine compartment in general and can't find anything. Not sure what else can be done to diagnose the actual cause of the problem.
Well its saying bank one sensor one is weak, so I would go ahead and replace the one that you didnt replace, but did you clear the code the first time, (after you replaced the first o2?)
July, 3, 2008 AT 2:48 PM
Yes I did clear the code each time and it returned. I replaced it when the original sensor was in and it came back after a few trips. I replaced the top sensor and cleared it. Again it came back after a few trips. My understanding is that the top sensor is the primary feedback sensor and the lower one - after the cat - only follows along. What I'm trying to avoid is just replacing parts without doing any type of diagnostic.
July, 4, 2008 AT 7:28 AM
It is not easy to confirm which is the real cause unless you hook up a diagnostic scanner to test the sensors.
After market sensors sometimes do not match with Honda and usually both sensors are required to be replaced at the same time.
July, 14, 2008 AT 12:27 PM
Since code began appearing after clutch replacement, I concluded that most likely cause was due to a leak or a bad PCM connection related to the repair job. I cleaned and reseated all of the sensor connections and checked all of the vacuum hoses. Likely cause was bad connection to secondary O2 sensor. This sensor connection was cleaned and reseated and code was cleared. Has not recurred. Keeping fingers crossed.