P2096 code came back.

[timk225]

A few months ago I put a Pacesetter header on my 5 SXT ATX. It eventually carboned up the gaps and became quiet, now you don't know there's a header in the car except when the computer pulls fuel on gear changes and the sound reverberates back through the header tubes.

Anyway, the only real annoyance I ever had was the morons at the muffler shop. I had installed the header and its extension, crosscut the inlet pipe of the new Magnaflow cat and securely clamped it into place, and drove it 2 miles to the muffler shop to get the tailpipe attached. Those retards insisted on welding it up instead of crosscutting the pipes and clamping it as I directed them to. They couldn't understand why my way was better.

So they welded in a piece of 2-1/2" pipe to match the 2-1/2" cat, and welded in a new rear O2 sensor bung right at the outlet of the cat. Then they welded the new pipe onto the stock tailpipe about a foot back.

And ever since, it had the check engine light on for P2096, rear O2 sensor lean. I never worried about it much, since the rear O2 sensor doesn't affect fuel/air mix ratio. But I wanted the check engine light off.

It seemed as though leaks in their half-assed welding job was where extra air was entering the exhaust and tripping off the rear sensor.

I had reset the computer a few times and would only get 10-15 miles at most before the code and check engine light came back on.

So after 3 months of this, I went under the car with some 700 degree Copper RTV, and totally sealed up the welds at the rear of the cat and the O2 sensor bung. This time I made it about 150 miles with no check engine light, but yesterday it came back on for P2096.

Any ideas? I suppose it's possible I'm getting a minor leak at the front of the cat where the adapter meets the header collector, I'm going to Copper RTV seal that when I swap on my Magnum head and change the timing belt and water pump in a few weeks.

Also, those muffler shop morons were rewelding the rear O2 sensor trying to get it sealed with the O2 sensor installed. Could they have electrically damaged the O2 sensor by doing that?

What about one of those spark plug defouler tricks to make the rear O2 sensor shut up? How does that work?

[timk225]

Well? Any ideas? Huh?

[r/tguy02]

your last 2 setences are your best bet to look into at this point, i think one or the other will solve your CEL. the new exhaust shouldnt be causing it

as for a "how to" i think there is one on here for a defouler. its very simple, buy a spark plug defouler, drill it out so an o2 sensor fits in it and bolt it up

[jrumann59]

modern sells an O2 sensor defouler for $26 and probably $6 shipping