GM Muscle

iTrader: (9)

Picked up a 2000 Silverado with a 4.8. I noticed these problems when I went to open the truck up on the highway. The truck starts to detonate at about 4,500rpm, it will get about 6-7*, it will then throw a random misfire code. Bank 2 LTFT is about +16 and bank 1 is normal (at cruise and at WOT). I noticed that it looks like the dealer started to steam clean the passanger side of the engine then stopped. I think I might have an injector problem on the bank 2 rail (already changed plugs and wires). What do you guys think. The dealer said that they would take care of it but I'd like to check this out for myself first. Any thoughts?

BTW: My timing jumped to 30* before I got the retard, the truck appears to be bone stock though. My dad's 03 only sees 25* at the most.