Cylinder 6 Misfire – Chrysler Town and Country 3.6 FL FFV 2018

2018 Chrysler Pacifica Cylinder 6 Misfire

Hello. Here is history and problem:

2018 Chrysler Pacifica: Driving along no problem, near empty. Fill up 87 at a gas station. Drive about 15 miles and start to have misfires (P0306). I drive another 15 miles home.

In my old 2012 Chrysler Town and Country I had a similar issue (not right after a fill-up) and I replaced the Coil-On-Plug ignition coil and that solved the issue.

My first thought was this was the same situation. Unfortunately cylinder 6 on this car is under the upper intake manifold.

I pulled everything apart, replaced the ignition coil, put it back together and still the same problem.

I then thought it might be bad gas and the car started to have a “rotten egg” smell which apparently means either the catalytic converter is having a problem or the gas has too much sulfur in it.

I added some “Seafoam” and drove about 100 miles to start burning off the potential bad gas. I added 4 gallons of “Premium” 93 octane after driving, plus an additional Lucas treatment to reduce the ethanol in the gas, and drove another 20 miles home.

At first, after the ignition coil replacement it seemed to have settled down, but then the misfires came back. After half the drive it seemed to be doing well and then started to get worse as the drive continued. Normally, keeping it either under 1500 RPM or over 2500 RPM seemed to smooth things out.

The ONLY code is P0306. Nothing else.

Live data view did not show anything that I saw as out of the ordinary but I don’t read these values regularly.

Per AllData, the possible problems could be:

——————
FUEL DELIVERY SYSTEM
IGNITION COIL, WIRING, OR CONNECTORS
ECT SENSOR, WIRING, OR CONNECTORS
MAP SENSOR, WIRING, OR CONNECTORS
O2 SENSOR, WIRING, OR CONNECTORS
ENGINE MECHANICAL SYSTEM
POWERTRAIN CONTROL MODULE (PCM)
——————

My vote is for bad gas (although why is only one cylinder affected) and/or that cylinder in some way.

Connectors look fine, sensors are not reporting errors and live view shows sensors reporting data. Not likely mechanical, again no other codes and if it was the PCM then I think most of the cylinders would be affected.

Any insight would be appreciated. Thanks. 🙂

Thanks.

Brand: Chrysler
Model: Town and Country
Year: 2018
Engine: 3.6 FL FFV