I was not getting a SES light at all for about 15k miles on my test pipes. About 5 days ago I took them off put some gasket sealer on them and re-installed. Now I have the SES light. I am confused as to why this mite have happened. When I first installed my test pipes long ago I got an SES for about 2-3 days. But it has not come back once since. It has been 5 almost 6 days now with lots of driving and it still comes on every time. Any help is greatly appreciated!

 

What "gasket sealer" did you use? Some can foul O2 sensors.

 

If you put too much you might have gotten some on the O2 sensor.

 

I used PERMATEX, though I don't know the exact one I used right now.

I let the car sit for 2 hours be4 starting it up, and did the install with the o2's out. Though it could have gotton on them after I put them back in. I will take them out when I get a chance to see if they have sealer on them.