Off-road exhaust = NO check engine Light??
 

I just had the Mac Prochamber Hipe and Mac cat backs installed yesterday... Love the sound..although kinda loud. Anyway I drove it around quite a bit after getting it on, Id say about 60=70 miles and The "check Engine" light hasnt come on. I even ordered Mil Eliminators thinking I would need them for that. Anyone?

I put the mac O/R prochamber on mine and nevwer got a check engine light. I dont think it "HAS TO" come on, just the fact that it may come on.

The CEL won't always come on right away. Sometimes it will be immediately, sometimes in a few hours, days, weeks, etc. You will probably want to put the MIL's on anyways, so this way if the CEL does go on you will know it's most likely not due to the o/r pipe.

Good im happy to hear that.. was thinking my o2 sensors were bad. Well I got the eliminators if I need em:)

(Update) I was out on a date and driving her home and the CEL came on.. took its sweet ol time. Im going to scan it and make sure thats what it is tho to be sure.

Just wait, it will come on soon enough....

I've had my off-road X-pipe, and Flowmaster cat-backs on for nearly 2yrs now, and still no CEL..... I did get a CEL at first, but after reading the OBDII code, i had a bad O2 sensor. But after further inspection, I pinched the wireharness between the block and tranny when I did my clutch swap... Repaired it, and cleared the computers memory, and the CEL has never come back on after that..

that is because on the 94-95 models the o2 sensors are before the cats and read the same.

I have a '97 GT. Its had two o2's behind the pre-cats, and two o2's behind the last set of cats. There where 6 cats total.

Yep same here..

I missread he has a post 95 model---sorry. yeah it is suprising that they have not yet come on. My car only has 2 o2 sensors located before the cats, maybe you engine light bulb is dead:confused: