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Sybil

Code P0300 misfire code on car with 21k miles?

Reset. P0308 #8 cylinder now. Swapped coil pack with # 6. Still has a P0308.  Can smell the rotten odor occasionally out of the exhaust. Oh brother here we go....

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9 hours ago, Renfrick1 said:

Can you say fourtwentysix


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Yeah I can say it.  Shouldn't need it it yet. Car breaks sitting in garage....

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Replaced the crank and cam sensor because the were cheap. Didn't fix the problem but went from a P0300 to a P0308.  Swapped the  #8 coil pack AND PLUGS with # 4. Threw a P0304. Replaced the coilpack with a new mopar one. Did not fix the problem. Pulled the plugs, fouled from the failed coilpack. When these NGK's foul that's it..they are junk.

 

So # 8 coilpack failed , fouled the plugs so had to replace coil pack and plugs. If you are going to try swapping the coilpack trick to another cylinder, swap the plugs as well or you may get to buy 4 new spark plugs. :rolleyes:

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Update. Finally found the real cause for the P0300. PVC valve was sucking air where it screws into manifold. May have had 2 issues going on, failed coil #8 , vacuum leak at PVC .

 

Finally fixed!!!1

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On 7/11/2020 at 6:02 PM, Renfrick1 said:

Yay


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Sadly no. Car stared misfiring again. Ordered a new PCM and it wasn't program correctly.  I'm close to taking a flame thrower to this car.....

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On 11/18/2020 at 3:40 AM, MikeDCop said:

They're have a lot of issues with this code on the Jeep V6 engines too. They usual cure is replacement. 

https://carcomputerexchange.com/?campaign=753344802&content=379839825347&keyword=car computer exchange&gclid=Cj0KCQiAkuP9BRCkARIsAKGLE8UpnoHMOcZDrdRRelfhPgCK14_3clgTuehxOr30dYJS_TZyyde_6KIaAnQSEALw_wcB

B.S. continues. Ordered a refurbished PCM from here . Battery light is on and lights inside and out flicker when car is idling. Sent back for another one. Car idles up and down and no response at gas pedal . Both Junk.

Put the one that came with the car back in. Since weather change no CEL or misfire with the factory one which has to be the PCM .When it's hot outside it acts up.

Any suggestions on where to get a PCM? Dealer wants 1k.

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On 11/21/2020 at 8:36 PM, Hemi57 said:

You might try AJ Berge - AKA Hemituner or Mike Dobain at OST Dyno.....

Tried OST . They don't mess with PCM's on Challengers that old . Recommended dealer. :(

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Sent back the 2nd crap ECM. We cleaned the connections to the ECM  and put original back in. Car runs fine. Can't get the misfire to happen now. It's only 50* outside today.

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Someone on another forum suggested running a ground wire from ECM to the ground connector under the hood. Said corrosion can cause a bad ground. Sounds strange but did it.Also put hose clamps on all the ends of the catch can. Drive it quite a bit over the weekend and no CEL or misfire. Strange...

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