Engine Problem Flashing CEL p0300 code

blk05hemi · Sep 25, 2011

Hey guys got a problem that has been bothering me as i have to drive my truck everyday. I started getting a flashing CEL it comes up as p0300 multiple cylinder misfire woohoo! Plugs and wires have been changed runs 91 fuel throttle body is clean.

The truck runs pretty damn ****** like pulling hard running rough at stop or idle mostly at around 1500 rpm it runs the worst and after 2000 it clears up.

another thing is im getting a squeaking noise when backing up only

Any ideas guys id really love the help!

bigbadram1500 · Sep 25, 2011

I had a similar problem and ended up with the codes of cylinder 8 misfire and a crankshaft position sensor. It would kick and buck and start misfiring and I ended up on the side of the road with a flashing CEL and the whole truck shaking from it misfiring so bad. Scared the crap out of me. Ended up limping it to the dealer and got the sensor replaced.

quietpeen · Sep 25, 2011

when backing up where does it sound like the squeaking is coming from?

BlackedOutHemi · Sep 25, 2011

Mine misfired pretty bad for a whole day, almost took it in o get looked at but ended up going through the engine bay, found a loose ground that was causing the problem.

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HemiBabe · Sep 25, 2011

Hope you get it figured out

blk05hemi · Sep 26, 2011

Dropped the truck off at the stealership hopefully they will take care of whatever is wrong..

bigbadram1500 · Sep 26, 2011

Hope so too. I've had good luck with my stealership. Let us know.

blk05hemi · Sep 26, 2011

Stealership tried to steal from me so told em to shove it lol. They wanted $500 dollars to replace all four o2 sensors... Did it for about $120 and its runnin good

bigbadram1500 · Sep 26, 2011

500? Damn.

Glad you got her fixed yourself.

BlackedOutHemi · Sep 26, 2011

They tend to do that. Haha. Glad you got it worked out.

KGBIGCOUNTRY · Sep 27, 2011

The upstream ones would have caused it, the down streams shouldnt have though. Glad it was nothing major bud. Did any of them look fouled out bad?

blk05hemi · Sep 27, 2011

KGBIGCOUNTRY said:
The upstream ones would have caused it, the down streams shouldnt have though. Glad it was nothing major bud. Did any of them look fouled out bad?

Yeah they looked pretty bad lol. It was the passenger side upstream that was causing all the mayhem but i just replaced all four so i could get that damn engine light off finally.

KGBIGCOUNTRY · Sep 28, 2011

Hopefuly they wont to bad to get out of the headers.

avgjoetx · Dec 27, 2017

Had the same code on my 2008 5.7 and it started dying on me. In Dec 2017 it now has 65K miles. So it is lightly driven and garaged. It started off dying once a month. Then it would not stay running for more than a minute. I suspect the code was a byproduct of the engine dying. No other codes given. So I started the "sensor hunt" Replaced the MAP, 1st O2, intake temp, crankshaft sensor, and all the plugs (needed that anyway). One of the last two things seems to have solved it. 1. replaced the cam sensor. 2. loosened and tightened both battery ground wires. I cannot say for sure which one solved it but now it seems to be running fine. I will let you know if it does not pass the long term test. Next step was throttle body, I hope I can return that one but will hang on to it for a while.

Engine Problem Flashing CEL p0300 code

blk05hemi

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bigbadram1500

Senior Member

quietpeen

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BlackedOutHemi

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HemiBabe

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blk05hemi

Senior Member

bigbadram1500

Senior Member

blk05hemi

Senior Member

bigbadram1500

Senior Member

BlackedOutHemi

Senior Member

KGBIGCOUNTRY

Senior Member

blk05hemi

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KGBIGCOUNTRY

Senior Member

avgjoetx

Junior Member

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