P0302 code ... replace the ignition coil?

[John Galdieri]

i recently got a check engine light ... code is P0302 - Cylinder 2 misfire detected ... my trac is a 2002 with 145k miles on it ... i replaced the spark plugs and wires at 100k miles - thinking it could be the ignition coil ... should i try replacing that first .. any other ideas?



ps: thanks to people like you on this site I have done all the needed repairs on my trac

myself - great for someone with no formal training ... gotta love the internet and the love

we have for our tracs ... been wondering what i would buy if my trac ever died, but

there is nothing else out there that makes the same connection.

 

[Kevin Palmer]

Unfortunately, without testing things, it is a guessing game.

It could be an injector, bad valve, or ignition issue.



The ignition can be tested with a spark (gap) tester and the wiring to the injector using a NOID lamp. I would do a compression test, this way you will know if you have a physical engine issue or if it is one of the other components I mentioned.

 

[Todd Z]

If the coil was bad, it would be a 2 cylinder misfire....

The coil fires #2 and #6 At the same time...



My guess is a dirty fuel injector or bad plug or wire....



I would check that the wire on #2 and make sure it is set on the plug correctly and that the plug is not cracked....



Todd Z

 

[Kevin Palmer]

This is a NOID lamp (Light). It plugs into the wire harness in front of the injector and illuminates if the injector wire harness is getting power.



[Broken External Image]:

 

[Paul H]

Here is what the OBD code chart says for this CEL code:



The misfire detection monitor is designed to monitor engine misfire and identify the specific cylinder in which the misfire has occurred. Misfire is defined as lack of combustion in a cylinder due to absence of spark, poor fuel metering, poor compression, or any other cause.



Ignition system

Fuel injectors

Running out of fuel

EVAP canister purge valve

Fuel pressure

Evaporative emission system

Base engine



Best of luck



Paul H

 

[Tom Schindler]

Plug brand?





Tom

 

[Mat Deegan]

i also got PO301 - cylinder 1 misfire detected. i've been trying to fix it for about a week and I'm out of ideas. if you figured it out, please please let me know.



thanks

mat

 

[Tom Schindler]

Mat,



Have you replaced the plugs and wires? What brand of plugs did you use, provided you replaced them?





Tom

 

[Mat Deegan]

Tom,



the spark plugs and wires are about 4 months old. the spark plugs are motorcraft and wires are just some autozone brand. i don't really want to take it to the dealer after all of the spending during the holidays. this sucks



Mat

 

[Tom Schindler]

Have you tried switching the wires. i.e. move wire 1 to plug two and wire two to plug 1 and the same up top. If the code changes, you got a bad wire. If it stays the same, then swap plugs between the two. Same with the plugs. If it still stays the same, then you problem is something more.



Have you tried anything like that already?





Tom

 

[EddieS'04]

Iam not to keen on autozone wires. I wont buy anything except a spiral core wire. Brand has never matered as long as they are quality. That is usualy in the $40 to $50 range.

It is also posible of a cracked insultor just now showing up..been there..

 

[Mat Deegan]

ill try that ill might as well buy a new set of wire and try what Tom said. sorry terpnstn im not trying to steal your post since we have the same issue. it might as well helps both of us



Mat

 

[Tom Schindler]

MatD,



No need to buy anything. Just pull the wire from the plug next to it and switch them. Then do the same up top. If nothing changes, then you know the wires are good.



Switch two plugs. If nothing changes, then you know the plug is good. If the problem moes to another cylinder, you know what is wrong.



Really simple.





Tom

 

[Mat Deegan]

problem solved!!! cylinder 1 had a bad wire. i switch from cylinder 1 to 2 and went back to autozone and pull the code. guess what cylinder 2 now misfired. so i went back inside and bought a new set of wires. now my truck runs like new



thank you all

 

[Todd Z]

isn't it amazing how a simple test can fix a problem that the dealer or the repair shop would beat you up on...



Glad it is fixed...



Good call Tom...



Todd Z

 

[Tom Schindler]

I suggest that to everyone that has an issue like that.



I have seen bad plugs or wires right out of the box.



That is the easiest way to confirm a problem. The wires are already run from the coil to the plugs. If nothing changes, then try the plug. If still no difference, then the problem is something else.



No extra costs involved.





Tom

 

[Mat Deegan]

good info. thanks Tom