I have 2000 chevy silverado 2500 series 4x4,6.0 liter.my check engine light keeps coming on. ive changed the oxygen sensor,plugs,wires,complete tune up. i all so changed the coil packs on cylinders 1 and 6, still reading multiple,multiple missfires on 1 and 6. what could be my problem.

SOURCE: 1998 Cavalier 2.4 L stumbles and misses at 2000-2500 RPM

Vacuume Leaks can cause this problems. you have to do a through check of vacuum hoses and the EGR valve. Your best bet can be to have your vehicle scanned at an autozone store and get a code. The EGR has to be closed at idle, then as the engine warms up or is accelerated, the EGR opens. That is if your car does not have an electronic EGR . The electronic EGRs do not use vacuum to operate. They are controlled by the PCM (power train control Module).

Zak Hanson-Michelson

• 35 Answers
• Posted on Jan 08, 2009

SOURCE: 98 Cavalier 2.4L engine stumbles at 2000-2500 rpm

Could be a short in the wiring for the O2 sensor.   I currently have the same issue only my car finally threw a code after two days of it acting up.  Code 106.  Changed the MAP sensor and it now throws 108, MAP sensor high voltage circuit.  Ah the joys of cold weather and broke down vehicles.  But I know that you wont always get a code with a short.  Let me know if you fixed the problem.

SOURCE: I have a 1997 Chevy Cavalier with a 2.2 Liter

Sounds like either the ignition module and or a coil pack is the culprit. I dont remember what year they changed it but if your is the one where the coil packs/module are located on the back of the motor they are a little tricky to get to. You need to remove dog bone mount and replace with a tool that will pull the motor forward so you can gain easier access...good luck. Hopefully yours are right on the top where they should have been since day one... :-)

SOURCE: which cylinder is #8 on the 6.0 liter V-8 Chevy Silverado ?

passanger side against firewall. gm's use the same number pattern for their cylinders on the V8's. Front drives side is one, front passangers side is two, second drivers side is three, second drivers side is four, and so on.

SOURCE: 2003 Chevy Venture misfiring

The injector is a good possibility, although you should check for spark in the wire first, as the electrical is the weakest link in the system. Put a spare plug in the end of the wire with the plug resting on metal, then have someone crank the van to see if you have spark that far, test and replace spark plug, (do not get shocked!) then look into a new injector or a good cleaning.