AB,

Wife came home tonight with a CEL on, pulled the code and found a P0302, cylinder #2 misfire.

What's the best course of action?

Quick googling suggests checking the coil pack first by swapping the 2 that are alike (#2 and #4) and seeing if the code changes to a P0304.

If not - check plugs and wires?

Car has close to 100,000 miles on the odometer, so it's time for a plug change regardless.

TIA

Year?

Engine size?

Sorry, 2005 6i, 2.3L 4 cylinder.

Check the spark plugs first.

Coil pack.

quote:

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Wife came home tonight with a CEL on, pulled the code and found a P0302, cylinder #2 misfire.

What's the best course of action?

Quick googling suggests checking the coil pack first by swapping the 2 that are alike (#2 and #4) and seeing if the code changes to a P0304.

If not - check plugs and wires?

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You do not have a coil pack, nor do you have wires.

A Coil pack was used on Distrubutorless ignitions before COP (Coil on Plug) technology came into play, which is what your Mazda6 is equipped with.

The Coils can be swapped from location to location. You can do this, and see if the misfire follows.

How many miles on said engine? Over 60K, may be time for plugs anyway.

coil/coil pack same difference... that's probably what's the problem.

Yes, I meant the individual ignition coils.

Possible causes listed on the service manual I found include:
Spark plug malfunction
High-tension lead malfunction
Fuel injector malfunction
Air suction in intake air system
Inadequate engine compression due to engine internal malfunction
Related connector or terminal malfunction
Related wiring harness malfunction

The first five steps to diagnose include using an OBDII scanner...

I've got an order waiting for me to pick up at the parts house this afternoon. Plan to change plugs and wires first since I can't find my OBDII scanner, if that doesn't help, I'll reset and swap the ignition coils then take it to have the code pulled again.

Thanks for the help.

quote:

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Plan to change plugs and wires

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You dont have any spark plug wires.

Put Motorcraft plugs in it.

Excuse me, high-tension leads.

I've got some NGKs and Motorcraft on hold since I've never bought the Motorcraft plugs before. Are they better than the NGKs?

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Excuse me, high-tension leads.

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???

Are you talking about the coil boots?

2.3L MZR Engine = 2.3L Duratec Engine.

Use the Motorcrafts.

#6

[This message has been edited by Aggietaco (edited 10/3/2012 4:04p).]

So apparently 2005 Mazda 6 came in two flavors.

One had a COP design (California Emissions) and Federal, (coil pack and wires).

I stand corrected.

More than likely the coil is fine and the culprit is bad plugs/wire.

Borg Warner cables and Motorcraft plugs should get her running good again.

Got the plugs and wires replaced, didn't throw a code in the 20 minutes or so I let it run. Only issue is there was some oil in the #2 and #3 spark plug holes, so I'm guessing the valve cover gasket needs to be replaced.


New plugs and wires installed on this massive motor:


Old plugs in order from top to bottom. #2 was loose.

And thanks for the help 1ags. Went with the Motorcraft plugs per your recommendation. They didn't have the BW wires, so I just picked out some Autolites.