Hi guys, I have a 98 z71 5.7 liter. About a month ago it started skipping. I replaced plugs and plug wires which yielded a slight decrease in the skipping. I then bought some C-foam fuel injection cleaner from AdvanceAuto. The truck ran better for about 3/4 of that tank of gas approx 200 miles. It then started back skipping, and finally cranks for 1-2 seconds and immediately shuts off. I pulled the obd2 codes and had p0420, p0440. The cat conv has been removed which yields the p0420. I also traced down the p0440 problem by replacing a return hose to the charcoal canister. Next I took a fuel pressure gauge, and got a reading at the fuel rail of 52 psi when the key is turned to the on position. I left the key on and re-checked the fuel pressure in 10-15 mins and the fuel pressure read 48psi. Do any of you have any ideas where to start next? Also this is a 98 model vehicle, which does not have the chip in the key therefore, I don't think it is a passlock type issue.
have the same problem?
Wednesday, January 27th, 2010 AT 9:10 PM