tagz

A few weeks ago, my car started stumbling like crazy out of no where. Had a feeling it was an o2 sensor, cause it only happened when the car hit closed loop. So I data logged it and sure enough, it through a code saying "Right o2 lean"

To insure that it was a bad o2, and not the right side actually running lean... I switched the o2's around. And sure enough... the left o2 was now lean. So i replaced the bad o2. At this point, the new o2 is on the left side. And the good, but 1k mile old o2 is on the right side that WAS throwing the code.

Both of the o2 sensors were AC Delco, and had less then 1k miles on them. Both were spliced, with solder, wrapped with heat shrink, and electrical taped to ensure a good clean connection.

Now, 3 weeks later, I am having the same exact problem. And again, it is throwwing the same code 64: Right o2 lean.

What can be causeing the right o2 to die on me like this? Is my current a/f mixture running too rich and clogging that o2? Is this possible?

Lt1t56

I had a code 44 problem not long ago, same as code 64 just on other side of motor. If your problem is like mine the O2 is working properly and indicating a problem, exhaust is lean on that side. My problem only happened when car reached operating temperature. The header on the left side was sucking air from the slip in tube in the header and causing problem, my guess was that the heat from the motor was causing enough expansion in the slip tube to create an air leak. Tryed tightening up clamp on slip tube but didnt help, replaced clamp, tightened it extremely tight, problem solved. It was kinda strange never heard any exhaust leak from engine what soever. My suggestion would be to look for any type of exhaust or air leak on your header or manifold what ever you have and make sure the O2 sensor is tight. Your O2 is seeing a lean conditon because the air entering the manifold or header isnt being monitored by the MAF sensor. Hope this helps ya.

Injuneer

He already explained that he switched the O2 sensors side-to-side, and the problem followed the sensor. That would rule out an exhaust leak.

Just to check, did your scan show high BLM's on the side with the faulty sensor, and normal BLM's on the side with the healthy sensor, and did the BLM's switch with the sensor move?

Are you saying that you are adding splices to the sensor wiring? Might be damaging the sensor when soldering, or screwing up the vent connection that allows outside air into the membrane of the sensor to make it operate. Generally, you should extend the harness wiring, not the stainless steel wires on the sensor.

Just a thought.

juiced_lt1

not to scare you, but a blown head gasket can ruin it, because contaminates (like antifreeze) will get down the exhaust and screw them up. That would explain why the right one died again.

tagz

coolant level = good

but i'm thinkin its the oil leak i have on that side of hte engine. pretty sure it is a vvalve cover. oil is probably covering the o2, and the o2 wire.

if you would like to look at the log here it is:
http://www.tagliasautoparts.com/713bado2.uni