2001 Chrysler Voyager LS 3.3L With a miss in it but all the time soI have changed all 6 Spark plugs Wires &coil pack The fuel filter at the tank ,air filter & miss was gone a few days later the miss is back had it put on a engine scanner no codes come up &everything shows good but the miss is there yet Do you have a answer thank Bill %73 470-0965

Make sure computer was cleared from old error. Check or replace #2 fuel injector. Spark plug wires can be replaced individually, you might want to replace #2 wire.

A defective signal wire from the processor.

everything unnecessary as the problem is the injectors /fuel pressure or injector wiring
run the fault codes first and save money

P0304 Cylinder 4 Misfire Detected,A code P0304 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• Defective computer
• If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs).. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced.

When you changed spark plugs did you notice any oil on the insulator or wire plug? Or any oil in the hole that the spark plugs are in? This model of LS were built with gaskets that seem to always fail. Lincoln came out with new gaskets in 2002 or 2003. If there was any oil in the above mentioned places your coils (COP Coil on plug) could be shorting out due to the oil degrading the insulator on the cops.The fix for this is to replace the valve cover gasket set with the upgraded set. Also it's almost impossible to find which coil is bad, and I recommend replacing all eight of the COPS. You can find them online pretty reasonable. I have used these and they seem to perform as good as the Dealer parts, but at a fraction of the cost. This solved the problem on my 2001 LS V8. Also these cars are known to have problems with the timing chains, which could also cause your problem. The adjuster shoes that keep the timing chain tight are plastic and wear out and come loose. Some times causing the engine to jump time and in the worst case could allow the pistons and the valves to come in contact. That will destroy the engine.

I would check the connectors on the coil packs, spark plugs and wires and replace them if they at all seem worn or tired. My 2000 sportage ran rough so I replaced the fuel filter, coil packs, spark plugs and wires, cleaned out the IAC valve, TPS, throttle body and intake tube, tightened the screws on the fuel pump access door under the right rear seat and cleaned the ground wire and the contact surface and I added 1 ground wire from the block to the firewall and 1 from the valve cover to the firewall. Your timing is more than likely right where it needs to be but the ignition may be slightly missing from a bad coil pack, dirty or fouled plugs or a bad plug wire.

if is runnig the PCM is not the problem,change the coil pack or the crancshaft position sensor.
the PCM is very expensive(500+) but they hardly go bad. PCM(power control mudule)

one more thing,have you tried the spark plug wires?

You have one coil pack for all 6 plugs:

Did the engine light go on, and you got a miss-fire code? If so, 1st check spark plugs (which u did), then plug wires, if that's not it, the injectors would be next. Let me know how u make out
Curt

If it skips just sometimes, then it could be the spark plug wires, if you change the plugs then its good to change the wires. Also take a timing light and connect to each of the wires one at a time, and rev the engine. Watch to see if the light skips. (an irregular flash) If so then trace the wire to the coil pack and replace the pack. Also anytime you replace spark plugs replace the fuel filter, air filter, and pvc valves.