garrett376

I am curious, when the O2 sensor is on the way out, does it (or can it) act intermittently? I will get a check engine light every once in a while - sometimes at idle, sometimes at a different speed, like 2880 RPM. I will check the code with the Hammer and it tells me that the sensor error is due to the O2 sensor open circuit/not present. But when the check engine light goes on, it will go off in a few seconds. The car drives perfectly, even when the light goes on, then goes off. I can watch the values of the O2 sensor while driving - it seems to oscillate just fine. It just keeps throwing a fault every once in a while, always the same error, according to the Hammer.

Is my O2 sensor on its way out? The wiring seems intact, as the plug is firmly attached... I guess I can swap out the sensor from my other car to check, but I thought I'd check with you guys first! Thanks

Indycam

It sounds like you have an Intermittent open . It might be going open for a millisec or less . You might not ever see it but the computer might . The open could be anywhere , from inside the computer back to the O2 sensor and then back to the insides of the computer .
Tracking down something like this , an Intermittent/Intermittent , is a test of your skills . Step by step , you can hunt it down .

You could do what the guy up north did , unplug the O2 sensor from the computer
and then redo the settings inside the DME so that the computer does not look for an O2 sensor .

Smokin

I posted a DIY article for 02 sensor change... It has a link a link where I purchased mine for a great price! Hope it helps!

https://rennlist.com/forums/diy-964-1989-1994-911/208133-diy-oxygen-sensor-replacement.html

garrett376

Wow Rick, that is one long thread for unscrewing one thing!!! Well documented!!!

How does your el-cheapo sensor work from www.autopartsworld.com? I've heard of cheaper O2 sensors not being the right type, especially if they get wet. Has it worked OK for you? Thanks

garrett376

Oooh, it's $106.34 now!

David P

I was getting black smoke when my O2 sensor failed.

DavidP

Mavel

My resonance valve flap did not open at 5500 rpm , when my O2 sensor was broken.