Dodge Challenger Forum banner

2011 Dodge Challenger SE PO300 and PO171 codes

6K views 4 replies 3 participants last post by  GlennW 
#1 · (Edited)
I have a 2011 Dodge Challenger SE 3.6L and It is logging codes PO300 and PO171. We had taken it to the Dodge Dealer when it first happened and they checked the Head because of the recall. They said it was good and it had 155 pounds of compression and no leak down. They said it was the PCM. We replaced the PCM and still logging the same codes. Since we have replaced the IAT and MAP sensor, intake gaskets, and O2 sensors. My husband also pulled the exhaust and the catalytic converter was plugged up so he took the inside out of the converter to see if that was it, still same thing. The car runs great except at an idle it runs real rough. He has also cleaned the injectors and even switched sides to see if it would change. We have checked for vacuum leaks and can't find any. We have changed spark plugs and one of the coil because it was bad. We have also replaced the cam sensor. We are stumped. The dealer has no idea what it could be. Anyone had this problem?
 
#2 ·
P0300 = random/multiple cylinder misfire
P0171 = System too lean - bank 1

Since the 3.6L doesn't use a MAF sensor a vacuum leak in the intake manifold should typically cause a rich condition and not a lean one. Now that the cat has been gutted the car isn't going to run right, either, so no use trying to diagnose the problem with an emissions/exhaust deficiency still. If the cat was plugged (A sign of some other problem) then it should've been replaced, not damaged more. Now you've got the PCM all confused because the O2 sensors aren't reading correctly and it's trying to compensate.

Your car has 2 cats, too, not one, so that makes things even more unbalanced. Get your cat(s) fixed and then resume troubleshooting.
 
  • Like
Reactions: pinkchallenger
#4 ·
Found problem PO300 and PO171

Ok this the last thing on the list. There is a fuel filter inside the fuel pump that is under the passenger side rear seat. You can't just buy the filter you have the buy the whole pump which was 180.00 at the Dodge Dealer. This fixed the codes!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top