P0303 code

[TexasMojitoRubi]

2020 rubi with 28k miles. Pentastar v6 motor. P0303 Cylinder misfire code is on. Jeep is running like crap. Spark plug and coil or something worse? Any tips on other issues that happen with code.

Links to other threads if applicable would be appreciated.

Yay. Jeep life.

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[Offroad-Hero]

Friend had the same error code when we went out to GA last week and he hit a mud puddle.

Could be if you have an aftermarket cold air intake that it pulled dust or water?
Could be your spark plugs need to be replaced?!

The P0303 code in a Jeep Wrangler indicates that cylinder 3 is misfiring or randomly misfiring. Possible causes include intake leaks or faulty spark plugs on cylinder 3. It is a drivability concern that should be addressed promptly.

 

[TexasMojitoRubi]

jeebus: gone down the rabbit hole of P0303 in the pentastar. not looking good for good guys. fingers crossed its the easy stuff

 

[TexasMojitoRubi]

Swapped the coils btw 1 and 3. Misfire stayed on cylinder 3. Crap. Swapped the plugs btw 1 and 3. Misfire jumped to cylinder 1. 11 bucks later a new plug is installed. Bazinga. Success. Got lucky.

 

[58Willys]

Swapped the coils btw 1 and 3. Misfire stayed on cylinder 3. Crap. Swapped the plugs btw 1 and 3. Misfire jumped to cylinder 1. 11 bucks later a new plug is installed. Bazinga. Success. Got lucky.

Nice diag job. What did the dead plug look like?

 

[Idaho Explorer]

2020 rubi with 28k miles. Pentastar v6 motor. P0303 Cylinder misfire code is on. Jeep is running like crap. Spark plug and coil or something worse? Any tips on other issues that happen with code.

Links to other threads if applicable would be appreciated.

Yay. Jeep life.

I hope it is not your case but my 2019 JLU R started with the same problem last December with about 115K miles. Then loss of coolant and overheating.
Diagnosis a blown head gasket and defective block. Teardown revealed three of the four cams were badly worn requiring a new engine. Now about $12K and 9,000 miles later I get another cylinder misfire code and it is going back in to another shop for engine teardown for metal in the oil and right bank very noisy. This is a known problem with the 3.6l Penstar engine. Anybody else thinking it is time for a class action suit against Jeep!!??

Check out my earlier post for pictures in January.

 

[TexasMojitoRubi]

So you’re saying sell the car asap. Haha.
Here’s a pic of the spark plug.

 

[TexasMojitoRubi]

Random dead spark plug at 28k miles did not sit well with me.


Combustion test failed.
Busted head gasket at 28k miles. Jesus Christ.

 

[mwilk012]

Random dead spark plug at 28k miles did not sit well with me.


Combustion test failed.
Busted head gasket at 28k miles. Jesus Christ.

Warranties are there for a reason, it'll buff out.

 

[TexasMojitoRubi]

Warranties are there for a reason, it'll buff out.

warranty is expired unfortunately. prob just going to take a loss and dump it. sad day.

 

[58Willys]

You must be barely out of warranty. I would go to dealer and see if they will do a good will fix. Obviously a major factory defect. Sorry.

 

[Idaho Explorer]

Random dead spark plug at 28k miles did not sit well with me.


Combustion test failed.
Busted head gasket at 28k miles. Jesus Christ.

At least you are under warranty!

 

[TexasMojitoRubi]

5 yr warranty expired in march

 

[TexasMojitoRubi]

i think i've talked myself into swapping the gaskets. might be a "fun" little project. Car never overheated so hopefully nothing is warped.

 

[sherpaJL]

i think i've talked myself into swapping the gaskets. might be a "fun" little project. Car never overheated so hopefully nothing is warped.

cool. take us along for the ride.
out of warranty, I'd do the same thing.

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