Im new to this mechanic stuff and im not sure wht im doing or how to go about this. I have a 2003 5.3l Silverado. Im using a 2Launch CRP129E scanner and have readings of my 02 sensors. Truck runs like crap, timing is advanced and throttle body says its open at 8%.
Trouble codes are:
P0135
P0449
P0463
Any advice? Thanks.