I got a 03 ecsb with a 5.3 that has a rough idle, and no ecu code. It only does it while I'm in drive with the brake on. I was thinking maybe a vacuum leak. The truck is bone stock.
Printable View
I got a 03 ecsb with a 5.3 that has a rough idle, and no ecu code. It only does it while I'm in drive with the brake on. I was thinking maybe a vacuum leak. The truck is bone stock.
Plug wires, plugs, check your injectors, possibly o2 starting to go out, possibly a clogged cat.
Clean your throttle body first - then look at the other items listed.
Idle misfires are usually fuel or injector related. Acceleration or load misfires are usually ignition related.