New Exhaust and a check engine light!

[k2mountain]

So I put a new LC exhaust into my 94 Toyota pickup last weekend and I had some trouble with leaks forming around the 's' shaped pipe and the u bolt clamps. I haven't had a chance to fix the leaks yet that's coming this weekend but last night my check engine light came on. To me it seems the the leaks my be responsible for the engine light? Has anyone else had a check engine light come on after installing a new exhaust, or engine lights coming on as the result of an exhaust leak? I've checked minor things such as oil levels and coolant and everything seems fine and the engine sounds good.

[stump runner]

I'm guessing bad O2 sensor. I think itwould take some pretty major leakage to throw a code. possibly some contamination got into it like welding smoke or burning oil film from fabrication process

[k2mountain]

yeah I was wondering about that too. I replaced the 02 sensor about 4 years ago so I guess its been awhile.

[ToxicToy]

not to mess up this thread or anything, but my check engine light always stays on when its done warming up and driving it?

I have a 22re 85' with auto

It does not help much when I put the battery in backwards and fried the original cpu :bluecryin on top of that I blew my main fuse in the fuse box under th hood, and replaced with a new one, and tried it no worky, my mechanic installed another used cpu from a manual truck, and it started and stayed on and seems ok, expect now for the check engine light, he said that the cpus from auto and manual are the same, which i beg to differ, i dont think they are the same otherwise it wouldnt have the check engine light?

I pulled the fuses to try to get rid of the light, but not disabling it, what could it be, my mechanic said the afm/maf which i dont think is correct, i installed a used maf/afm from a member on marlin, and it doesnt do the trick

any other thoughts? sorry for the long post, i thought i would post since its the Check Engine Light topic, btw it runs fine and no problems yet, its been about half a year running with that light on, annyoing, but i just think its the manual cpu thinking different becasue of the auto?

Thanks :dunno:

[stump runner]

of course it would make the most sense to read the codes before randomly replacing stuff.
http://www.off-road.com/toyota/tech/codes/