O2 sensor light when cold

[tommydogs]

Hi, I searched the forums and couldn't find exactly the problem I am experiencing now:

I start the car in the morning in my apartment garage, back out, slowly drive to the gate and wait for it to open. Drive about 1/2 mile to stop light (where I've stopped), and the CHECK ENGINE light comes on (later identified as passenger bank O2 lambda sensor code). I start driving and the CHECK ENGINE light goes out and never comes on again (until the next morning). Given this evidence, what could be the most likely culprit?

I've just had throttle bodies cleaned up. That code has been thrown the odd time or two before that, but is now occurring "regularly".

[m6bigdog]

It could be the O2 sensors. IMHO the O2 sensors should be changed at 60K miles. Any more miles than than and they start to drift and lean out the idle and part throttle causing all the things that come with a lean burn.
Or, it could be the intake manifold gaskets or other intake leak. I changed the intake manifold gaskets at 80k miles due to the symptoms of an occasional slight miss with an CEL during engine warm-up.
You can use a can of Dust-Off to diagnose the intake manifold gasket leak. Slip a 2-3ft length of 1/8" hose over the pin nozzle, start up the engine while cold and spray some of the inert-gas around the base of each intake runner to see if the gas effects the engine idle smoothness.

[Timm]

If you have INPA diagnostics:

[tommydogs]

Thanks. My O2 sensors must be less than 60k miles, as I got my car with 80k and it is now about 130k. Sometime in between I know they've been changed, but not exactly sure when. They could be pretty old, however, as I've had the car for over 17 years.

Stopping over at the hardware store and picking up some compressed air and vinyl tubing should be something I can handle. I'll give it a shot and report back.

- - - Updated - - -

Thanks, Timm. I don't have the INPA diagnostics, but watching the video and seeing all the data it can collect really makes me want to go out and get it.