Code P0135 On Civic

Primary oxygen sensor is the one closest the engine.

"Frank van Hoof" wrote

From general reading and rough recollection, buy only OEM.

Before buying, get a manual and go through the procedure for diagnosing this code. Codes don't necessarily identify that a component like the O2 sensor has failed and needs replacement. Could be just a loose wire somewhere. Have you other symptoms of a failed O2 sensor (like inappropriate engine revving)? Bad fuel mileage?

I found an OEM one that was a steal at

.Put it (a Denso, which is OEM) into my 91 Civic last year. Yours appears togo for $70, tops, at this site. Goes for over $150 at Majestic Honda partsonline.

OTOH, I wouldn't say you are throwing money away by replacing a seven-year old O2 sensor. I've read they do degrade in performance over time, though mine lasted 13 years and may have been able to go longer.

stick with oem sensors. aftermarket like bosch will get you through emissions, but their reaction times are very poor compared to oem, and performance consequently sucks. i did some experimentation with different sensors i'd got from a junkyard. no doubt about it, oem is the way to go.

I did a Bosch/Denso experimentations. Their response time is about equal on an analog voltmeter. I might record their response time on a dual digital scope in the near future. A $225 Genuine O2 sensor could beat out the $49 Bosch, but by how much is the question.

As long as the fuel/air supply are clean and no or little oil or radiator fluid consumption, the Bosch can last more than 200K.

that would be excellent!

indeed. my test was limited to "drivability" which meant two things on my automatic: hesitation and smoothness of gear shifts. the first, i kinda hoped for, the second i was not expecting at all. when i first got this 89, it had been filled with non-honda atf and had the old "shift like a door slamming" feeling. i'd changed the atf back to honda three times and the shift was a lot better, but still a little harsh and i figured it was probably due to permanent contamination of the clutches. when i changed the sensor however, suddenly, the harsh shifting improved dramatically!!!

can't say i have the patience for the longevity test. my sensors are single wire unheated - that may have some influence on results.

Interesting! I hadn't considered the effect of O2 sensor response time on changes like throttle changes or shifting. It makes sense, though. That also means that old O2 sensors are likely to affect shift smoothness and throttle response, since slowness is a common "failure" mode.

Mike

"Michael Pardee" wrote in news: snipped-for-privacy@sedona.net:

Could this be "Jez's" RPM oscillating problem?

Or could be that the O2 sensors are making the car run a little lean (instead of slowness in response.) Second generation Hondas tend to not shift well under lower horsepower. You could try advancing your timing and you can feel the slamming door shift. My original O2 sensors at 270K miles does a good job with accelerations and shift smoothness.