I recently have been having a problem with the CEL due to a faulty O2 sensor which I thought I fixed with an aftermarket sensor. However, the CEL came back on and then later after about 125 miles went out again. I was driving on the highway to Oklahoma from NY so this was an extended trip. for the majority of the trip the CEL was off, 5-600 miles or so and then on again for about 125 miles, then off again. What is going on? Going crazy here trying to figure out what's happening.:screwy: The aftermarket sensors are terrible to hook up, I would suggest using OEM fom now on. But there on back order.

Go to Autozone and get your CEL code read - post back what it is.

what year/model/engine ect...

I used a Bosch with the OEM connector and it worked perfectly. Was only $50 too, so not so bad. Like RF said, go get the code read for free because it may be a different code all together.

marc

Since you were going on a long trip me thinks you got a tank of gas... :grinyes:

...Just for fun check the gas cap, maybe during fuel stops it was loose at one point, after fueling up you corrected the problem, light goes out.

Just an idea.

-Phil

I recently have been having a problem with the CEL due to a faulty O2 sensor which I thought I fixed with an aftermarket sensor. ...

If it was a lean or rich code from one of your upstream O2 sensors, the sensor is not the culpret.

Joel

Got the codes read, P0131 and P0137. Same codes as when I first had this problem. Dealer won't touch it since I put in an aftermarket sensor. I was thinking that the EGR valve might be the culprit?

Did you get the O2 w/ the OEM style connector, like marcre suggested? Or did you splice the connector?

If you spliced, check your splice first!


Things to test...In this order.


-Check the harness on the O2 sensors you messed with (ie: check for corrosion and the pins being pushed back in the connectors)

-Try to hand-over-hand the harness wire back a ways, make sure the wires are not damaged (ie: laying against exhaust system somewhere).

-Vacuum hoses (splits/cracks)

-Check PCV for proper installation and condition (it should rattle, if you're brave, blow into the outlet (intake manifold side) and make sure it stops flow)

-Check the Mass Air Flow sensor (ie: no blockage in the screen)

-Check Fuel pressure

-Check Fuel filter (see above)

Good Luck!

-Phil