P0300 and cylinder misfires

killasteez187

killasteez187

New Member
Joined
Jul 6, 2022
Messages
20
Location
new smyrna beach FL
so recently i had a cylinder 6 misfire so i changed all the plugs wires and coil pack. now my code reader is saying multiple cylinders are misfiring. p0300. could this be bad plugs? wires? connectivity? or do i need to dig deeper? anyone else had similar issues?
 
If u did mopar coil and wires u would think that might be it. Hate to say for sure. These jeeps are so finicky with parts it’s ridiculous. I heard long ago that the ecm takes a little time to LEARN a new part when it has been replaced. I know now that to be true. I replaced a off brand purge valve with a mopar brand which too about 2 weeks before it actually cured my issue. Sounds crazy but it’s true. Having said that I did put NGK iridium plugs in my 07 on my last change and the Jeep loves them. Increased mileage and very smooth idle. It seems to me that mopar parts have just a little different voltage. Crazy right? You will get er ol buddy!
 
  • Like
Reactions: BLACKJKU
BigAL07 said:
If u did mopar coil and wires u would think that might be it. Hate to say for sure. These jeeps are so finicky with parts it’s ridiculous. I heard long ago that the ecm takes a little time to LEARN a new part when it has been replaced. I know now that to be true. I replaced a off brand purge valve with a mopar brand which too about 2 weeks before it actually cured my issue. Sounds crazy but it’s true. Having said that I did put NGK iridium plugs in my 07 on my last change and the Jeep loves them. Increased mileage and very smooth idle. It seems to me that mopar parts have just a little different voltage. Crazy right? You will get er ol buddy!
Click to expand...
dang thats crazy. see it did have mopar plugs before. maybe i should try some new mopar plugs?? thanks for the input dude! good to know
 
  • Like
Reactions: BigAL07
Definitely wouldn’t hurt. Be sure to double check the gap right out the box. BTW big GATORS fan here I WV!
 
  • Like
Reactions: mrjp
killasteez187 said:
dang thats crazy. see it did have mopar plugs before. maybe i should try some new mopar plugs?? thanks for the input dude! good to know
Click to expand...
The brand is irrelevant. There is no such thing as a Mopar sparkplug. They re-brand plugs from several companies, like Champion and NGK. Autolite is a perfectly good, reputable company.
All that matters is that the plugs you used are the right size, the right heat range, and are properly gapped. I've noticed that fewer and fewer people seem to gap plugs before they install them.
Since you've already replaced the coils/wires/plugs, you need to consider other causes. Like plugged catalytic converters, injectors problems, fuel pressure or pump failure, cam or crank position sensor...
 
  • Like
Reactions: mrjp and killasteez187
BigAL07 said:
Correct. I’m sure he is referring to the stock Champion plugs that came stock in the Jeep. I’m sure u would agree that any brand can have a bad plug straight out the box. Hairline cracks etc.
Click to expand...
Sure, absolutely, 100%. But multiple seems unlikely.
 
I hear ya brother for sure. Just strange going from one single misfire on cylinder 6 , changing plugs then getting multiple misfires. But it is a Jeep and we all know how that goes😳
 
  • Like
Reactions: killasteez187
BigAL07 said:
If u did mopar coil and wires u would think that might be it. Hate to say for sure. These jeeps are so finicky with parts it’s ridiculous. I heard long ago that the ecm takes a little time to LEARN a new part when it has been replaced. I know now that to be true. I replaced an off brand purge valve with a mopar brand which too about 2 weeks before it actually cured my issue. Sounds crazy but it’s true. Having said that I did put NGK iridium plugs in my 07 on my last change and the Jeep loves them. Increased mileage and very smooth idle. It seems to me that mopar parts have just a little different voltage. Crazy right? You will get er ol buddy!
Click to expand...
Do you have the part number for the plugs. Thanks
 
1276CA22-9297-4AFE-A59B-A5FE999B2D16.png
 
  • Like
Reactions: BLACKJKU
Top Bottom