o/r h-pipe install = leak and check engine light

[redwhiteanblue]

well the title says it. i put an o/r h-pipe on my car and i cannot get the collector/exhaust manifold to seal perfectly. the low and behold...the check engine light comes on. is this due to a leak? im not concerned about the leak due to headers being installed soon, but the engine light concerns me. is it drivable or will it get worse?any input appreciated. thanks. - austin

[theyallslow]

it could be the leak, did you put headers on also? and do you still have cats?
but if your light is on then it will just run very very rich tell somthing is fixed.

[redwhiteanblue]

i still have the stock exhaust manifolds on on it is an off road h pipe.

[theyallslow]

did you get the o2 sims? but try again and see if you can make it fit.

[Timido]

The only way to know for sure is read the code.

[NXcoupe]

If it is a 1990, then there are no down stream cats, so the sims won't do anything. Are the O2's new ones, the original ones out of your old pipe, or ones that came with the o/r pipe you just installed. Probably has something to do with that. Does the light come on as soon as you start the car, or does it come on after a little while?

[redwhiteanblue]

yes it is a 1990, the 02 sensors are from the new pipe, and the light comes on after it runs for 15- 20 minutes. the odd part is, no light came on at all when i ran the car w/o the h-pipe.