Been getting on340 and po344 can sensor codes since I got my 2006 expedition but never have found a cause. Found a post on here that a bad alternator could be the cause? Also once in awhile it will misfire at highway speed but not ever throw a misfire code, you can feel the vehicle jerk. Just recently started misfiring causing it to shudder and also seems to try to die. Getting po307 misfire on #7 , changed coils but didn't help. Don't believe it's a plug. I am hear a new noise near the #7 plug kind of a repeating sucking sound, wonder if the injector could be making it? Really hoping it's not a bad valve or intake gasket.
Annoying 340 344 codes and misfire
- Thread starter Impala60
- Start date
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your 06 & my 05 are notorious for cam phaser issues, the misfire might be an unrelated issue but dont be surprised if you're due for new phasers and vct's
Could be VCT solenoids, does it lug down and run rough at a stop sign or low speed?
Intake manifold gaskets ! And at the front metal bridge end pieces inside lips break and gaskets dont have any place to seated no more. If you see engine coolant around your injectors or coils, this is the indication its time to replace the intake manifold. I just did mine and got my t-shirt [emoji16]
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Yea thinking manifold gasket, I don't see any evidence but the weird sucking sound at #7 makes me think manifold or valve. Just trying to see if anyone has any other ideas. I do plan to change the timing parts just as maintenance since coming up on 200,000 and know it is a common issue, but since this misfire issue started , hoping I can resolve it simply. I really don't want to have to do anything major until spring. Thanks everyone for your input ,appreciate any ideas.
Thanks alot guys. finally got the miss sorted out . Finally decided to pull the plugs, they aren't very old, electrode was gone on one, the rest were ok. Still had the annoying 340 344 codes, but I just had a no start issue in checking discovered I have bad crank sensor wires and need to bypass/replace them. So I am now trying to find a pcm pin diagram, can anyone help
