I recently installed an off-road h-pipe on my car and now I get a Check Engine light, whats wrong with my car?
The stock catalytic h-pipe comes with 4-6 converters from the factory. There are 4 o2 sensors that tell the computer if the cats are doing their job. The first set looks at emissions and then compares to the rear set to see if the converters are doing their job. When you run an off-road pipe the readings never change so the computer senses something is wrong and trips the “Check Engine” light. There are several ways to fix this problem. First you can go with a set of MIL eliminators. These plug into your rear o2 sensors and basically fool the computer into thinking everything is OK. Option 2 is a custom burned chip. The chip can be programmed to turn off the rear o2 sensors among other things. This will also remove the light. Keep in mind with either modification, power must be disconnected for them to work.
