I can get it to go off with a battery discconect, but after a short time it comes back on. Is it on because the truck has aftermarket dual exhaust? What is a remedy?

1999 new body z71 4x4 3 door 120,000

 

What's the problem code ??
Did thid happen right after putting on the aftermarket exhaust ??
Did you include the O2 sensor ??

 

Golfer,
Bought it with the exhaust on it...don't know code or O2 sensor? Should I see what the code is first?
Jason

 

Yes.

 

Look at the exhaust. If you still have the factory cat and a electrical sensor (o2) behind each one. I am assuming you had dual to the muffler factory.
If you have a cat back exhaust you should be fine. Take it to Auto Zone or Advance Auto Parts they will check it for free. If it says it is lean or rich check the o2's but keep in mind a rich burn can mean a bad plug not getting a full burn or lean can be from a dirty fuel filter.