jgt01

2008 chevy Silverado
4.8 v8
had put on aftermarket air intake
no problems
finally had headers, hi flow cats, larger piping, flowmaster muffler
after exhaust was installed I started getting engine codes p1153 p1133 I believe a p0420 at one point before I cleared. I now have loss of power black sut out the exhaust. im presuming the vehicle is now dumping fuel. ive changed the o2 sensors has not resolved any ideas????

country_09

You need to get the air/fuel ratio recalculated bayou can't throw headers on and expect the stock tune to keep up with it. Needs a custom tune