2003 chevy truck rough idel changed alot of stuff

Question

I have a 2003 Chevy Silverado with a 5.3 it runs rough now. When I first bought the truck it ran good but it made a backfire sound out the gas tank area when I attempt to start it. Plus it would bust off fine sometimes. Then sometimes just spin over. I changed fuel pump charcoal canister the purge valve sensor behind the cab on the frame. I change cold air intake to stock breather with brand new mad sensor I changed fuel filter on the frame and new plugs plus a fuel pressure regulator on the motor. Now it doesn't backfire near tank. Starts right up but it feels like its missing and running rough. It also lost a lot of power. Please help

Answer 1

Hi there,

This could be an issue with a plugged catalytic converter, if there was misfires originally it can damage the converters. Also, check for intake manifold gasket leaks and you may want to check the ignition timing. If it's off then there will be a loss of power also.