P0303
So,
its not Distcap/rotor, not plug wires, not spark plug, not injector. At 60mph it hums real sweat.

I know I was advised to do a leak down test, but I would have to pay someone. Besides it only misses at hot engine idle.
So whats left?

 

Faulty coil pack
Faulty oxygen sensor
Faulty catalytic converter

if all else fails reset the code and see if the code comes back.

 

3.9L Dakota's do not have a coil packs. Just 1 ignition coil.
oxygen sensor and catalytic converter, wouldn't these components affect all cylinders? I have a misfire code for #3 cylinder only.

 

Id change plugs and wires, then see what happens from there.

 

How do you know?

You said it happens only when its hot. That makes me lean more toward an injector. If it were a plug or wire Id think you would see it all the time.

 

Because I replaced them all.

 

I've never got a new part that was bad


Trouble Code: P0303 (3.9L V6 VIN X Auto)
Cylinder 1-8 Misfire Detected

Print this code data
Number of Trips to Set Code: 1
OBD II Monitor Type: CCM Details
Indicators: MIL Details

• MISFIRE Details

Trouble Code Conditions:

Engine speed less than 3000 rpm, adaptive numerator updated, and PCM detected a misfire rate of 1% (High Emissions 2T), or a misfire rate of 6-30% (Catalyst Damaging 1T) in a single cylinder. Note: If the misfire is severe, the MIL will flash on/off on the 1st trip!
Possible Causes:

• Air leak in the intake manifold, or in the EGR or EVAP system
• Base engine mechanical fault that affects only one cylinder
• Erratic or interrupted CKP or CMP Sensor signals
• Fuel delivery component fault that affects only one cylinder (e.g., a dirty fuel injector)
• Ignition system problem (coil or plug) that affects only one cylinder

hope this helps

KillerKilgore

 

None of the links work????
P0303 is #3 cylinder misfire code.
1-8 cylinder misfire????????????? Unclear statement.

 

spyknee,

the "1 - 8 cylinder misfire code" that was mentioned is just a general outline of the error from a P0303 code on a 3.9L Dak, Auto.

Basically the error references a misfire somewhere 1 to 8, but specifically it's #3.

The links aren't working because they were pasted in, and javascript doesn't execute properly if referenced incorrectly

This should help: http://www.obd-codes.com/p0303

 

Just had a 2000 minivan that was trowing out a specific cylinder misfire code, Turned out to be the injectors field breaking down with heat.
When motor was cold ran great 10 mins of operation the miss was there.

But I know absolutley nothing so just offering similar experience