check engine light question

i just put an o/r x pipe on my 94 mustang. i also plugged the smog pump. on heavy accelerations the check engine light pops on.. then it goes back out. anybody know what this could indicate??

The O2 sensors need MIL eliminators........

it only has the o2 sensors that are before the cats to begin with neways. not the after cat o2s

i just put an o/r x pipe on my 94 mustang. i also plugged the smog pump. on heavy accelerations the check engine light pops on.. then it goes back out. anybody know what this could indicate??

I don't know what year 5.0 you have. However, I currently have mine torn apart. It seems there are two passages (one on each head) that mixes (pumps) clean air with your exhaust on the stroke. This air seems (I assume) to lean out the a/f mixture leaving your engine, and the cats are suppossed to do the rest. Seeing as how you plugged the pump, the reading is more than likely rich. (even before the cats.) This is just a guess, but I guess your burning a lot more fuel than usual? I am no expert on emissions, so someone correct me if I'm wrong. I am getting ready to do the same. I have posted a thread--theoratically this should work? but have yet to receive a response. Hope this helps.

Not to make it sound like I think you're an idiot or that I AM an idiot (by all means I may be) but did you do anything to the computer? I know these 90s stangs dont deal well with mods (even just exhousts) and can cause the engine mod not to work properly. I know I had to do that when I added new headers. Check that out.
Also, I also had the engine light problem (before the computer) and it could also be the O2 sensor, or could just be a slipped belt. Those are two previous reasons for my engine light to go off. Also, speeding at 115 and swerving from a pot hole made mine go off... as did the old joke, "Check engine?... Engine, check." And closing the hood... yellow lights piss me off...