I'm working on a 2006 Chrysler 300, with the 2.7L v6 (the internal water pump one). I just replaced the EGR valve due to a P0404 and surging while driving (verified with a scan tool the EGR valve would stick), while I had the intake manifold off I also changed the spark plugs (was not necessary but done while I had it apart). Now I have a couple other problems (to clarify these existed before swapping plugs and egr):

  1. At a warmed up idle the engine seems to shake and run quite rough, computer reports a P0301 as pending after running for a while, I swapped the coils from 1 to 2 but got the same code.
  2. Rough idle after filling up with gas.

For problem number two I assumed it was the purge valve sticking open and I put a new one on, unfortunately this has not seemed to fix the issue.

Now here's what's interesting, looking at my live data on my scan tool the engine only starts to run rough after the purge valve is opened, I don't seem to see any issues with fuel trims either (stay around 0). Also, the p0404 came back but seems to have gone away after unhooking the battery for 10 seconds and has not seemed to re appear.

Does anyone have any clue what this might be?

  • Perhaps a bad fuel tank pressure sensor or bad map sensor?
  • Maybe even a bad or dirty fuel injector?

EDIT: I also made sure the egr tubes were clear before I reinstalled them.

1 Answer 1


See of the connector pins might not be all the way touching inside connector. I would disconnect the sensors I had to disconnect with the intake removal and then reconnect them. Back probe with a voltmeter to see if signal and communication lines are working ok. Check the ground wires in the sensor. I had this problem more than once working on 2.7 300s

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