Urgent help! P0302 code

Ok guys well I changed my valve cover gaskets about 3 weeks ago and my truck has been sitting since then. I drove it last night and it felt like there was a miss in it but I wasn't throwing a code. Today I hopped in it and my CEL came on and now I am getting a rough, shaky idle and the code read P0302. I made sure all the plug wires were snug and all and it didn't fix a thing. Any help? I am supposed to be leaving tonight for a 1000 miles trip home to FL with it. Any help would be awesome!

 

0302 is misfire cyln. #2 right? Try first swapping wires from one plug to another (the entire wire, not just one end). Then swap plugs with another cylinder. Actually, take a look at #2 plug when the engine is cold. You might have just had some oil buildup in that cylinder? These are just the first few thoughts that come to mind...

 

Ok. I was going to replace all the wires for $37 anyways. Would that be a solid start?

 

It would be a solid start, but I would still at least pull the plugs and check them. Keep them in order so that you know what cylinder they came from. If all plugs look the same, then swap out #2 plug with #1 plug (Don't swap it with #3, because #3 is the companion cylinder for #2 and could falsify a reading sometimes) Go from there. Good luck!

 

the #2 cylinder is the middle drivers side correct?

 

also, if I switched a faulty wire to the 1st cylinder wouldn't it just move my miss to the 1st cylinder and I wouldn't know if it were any different?

 

If the problem follows the plug wire, the code will change. Same with moving the spark plug. If you move stuff around and the code never changes, it might be the coil pack, ICM or one of the cam/crank sensors. Or wiring...

 

Rats. Sorry to hear the issue is not cleared up from your other post.

I'd still recommend verifying all connections etc. for everything you had off while doing the VC job.

Did you put in new plugs? Just wondering there as some have had issues that way.

Great advise on above posts. Once you have made sure everything is correct, tight and connected as it should be.

Here is a link to a post that may help also. Gives cylinder numbering etc. http://www.yotatech.com/f2/firing-order-3-4-help-47016/ Third post down is the Haynes manual page.

Possible you could have damaged a wire while pulling them off? Set of new wires could not hurt as is the great advise about checking the plug condition.

The P0302 code is for cylinder 2 misfire.

 

and the problem goes to......."drum roll"......... Cracked wire boot on cylinder number 2




Thanks for your help guys!

 

Welcome....Glad to see you found the problem.

 

Hooray! Glad when an issue is simple!

 

Zombie thread!!!

I encountered a P0302 while driving home yesterday. @BamaToy1997's advice is solid. I wound up swapping coil packs, plugs and then plug wires keeping track of each change for comparison.

My issue wound up being a blowout through the #2 plug boot. I confirmed the problem when I swapped #2 and #4 wires. The issue moved to #4 and gave me a P0304 code.

Since my plugs were over 30k miles, I performed a full replacement with NGK plugs and wireset, replacing the damaged Duralast wires.

A note for you all: Advice across the web suggests that removing plugs from a COLD engine is best practice. I found that #6 was difficult to unthread, and wound up using WD40 while rocking the plug back and forth, slowly working it out. The plug felt smooth but tight during removal, never feeling like the plug was chattering against the aluminum threads of the head. After removal it was found that the plug had some carbon buildup on the threads that easily cracked off with a fingernail.

Pictures will be added later.