I've searched around and found that many of you get a code after you install your header/downpipe combo and unfortunately I've joined the party. I know you can get it taken care of with HPT, I've had that done with a past car, but I'm not willing to pay a few hundred dollars just to have that deleted for me. Plus I don't think anyone in the area is confident in tuning a 2.4L anyways (NoVa area).

I've heard of a few other options though, one being an electric bypass the other is some kind of addon piece to the O2 sensor bung to fool the computer? Can anyone point me in the direction of either of those? I can't seem to find the links on here anymore.

Chris

 

There are some threads on this -- need 2 anti-foulers for spark plugs to make it work. Search for the threads.

This is from another Cobalt forum...I don't take credit for it, just copying and pasting since we can't name the site:

STEP 1
-purchase 2 spark plug anti foulers at your local auto parts store
-18 mm size
-made by HELP brand / part number 42002 (around 5$)

STEP 2
-disconnect the negative terminal on your battery. this will reset your ecu
-take one of the anti foulers and drill out its center using a 1/2 bit ,
-this will increase its hole size and allow your stock o2 sensor to fit


STEP 3
-screw the drilled spark plug anti-fouler on top of the original
-be sure to use some kind of anti-seize on the treads. in case you need to remove your fix with ease

 

what kinda setup you got?? size dp??

 

CA 2.5" pipe w/ cat. The only other mod I'm running is a K&N intake, which whistles (kinda annoying) but never gave me any trouble otherwise.

Any pics of what that spark plug fouler setup looks like? Just in case a persistant mechanic decides to look at the underside of my car during inspection.

 

looks like a deep well socket with threads on one end and inside the other. ARK sells a CEL Eliminator that I know for a fact works, and fits a 2.5DP with no issues (from what i hear from others.) It simply threads into the O2 sensor hole in the DP then you put the O2 in it. Worked for my 3" catless DP; never had a problem/CEL.

 

Update 6/09/08: I got the ARK part but while I was doing my oil change today I took a look at how it might go on and to me it seems theres absolutely no way it'll fit. I didn't have a wrench big enough to actually take off the O2 but just holding it up next to the gap in the floor pan I don't see it happening. I'll have the mechanic take a look at it tomorrow at my shop but I have my doubts.