Check Engine Light came on with code P0306- misfire on cylinder #6 has been detected. Vehicle running normally without any noticeable stuttering. 100,000 miles, with newfuel filter, air filter, and spark plugs ~4 months ago.

I plan to start with replacingPCV & hose and cleaning the MAF. If that doesn't clear it, I plan to replace the ignition coil andplugon #6. Should I be looking at anything else?

Also, anybody know which cylinder is #6? Lots of contradictory info on the net. Unfortunately, it's on the rear bank for sure.

Thanks!![/align]

 

cyl#6 is on the bank closest to the radiator.
cyl arrangemment
firewall
(1)(2)(3)
(4)(5)(6)
radiator.
cyls 1&4 are closest to the pass side and 3&6 are closest to the drivers side.
coils failures were common. swap cyl 4 coil with cyl 6 and see if a code p0304 comes up
do not erase dtc memory (this clears the learned values the pcm uses to id which cyl is misfiring)
with the engine running reach back and feel the pcv hose where it connects to the intake. if it is collapsed replace
cleaning the maf is also a good idea. be sure to use a cleaner that will leave no residue.

 

If it seems to be running normally, throw some drygas in the gas tank (ethyl alcohol) and use up as much of the gas as you can. Refill with Premium and another bottle of drygas. Water condensation in the gas tank can sometimes build up and will cause the engine to misfire (just happened on my wife's car a couple weeks ago, I've had it happen on numerous other cars as well.)

It's cheap and easy. Give it a try and it might just work (saves you a lot of time and effort if it does.)

 

MPJ68: Thanks for taking the time to share theinformation. #4 and #6 on the radiator side is a relief.

 

hope it helps, ialways get stuck with misfires on the rear bank[sm=boosign.gif][sm=boosign.gif][sm=boosign.gif]

 

Update I cleaned the MAF, checked the PCV hose, and swapped the #6 and #4 ignition coil as suggested. The code remained P0306 (misfire #6) so it's not the coil. I also put in dry gas and injector cleaner as suggested, and will repeat at next fill up. CEL still on with below codes. Not getting fuel. Any other ideas? Thanks all!

P0306 - cyl#6 misfire detected
P0171B - Bank#1 system too lean
P0174B - Bank#2 system too lean

 

What do the plugs look like?

Whitish deposits indicate lean, black indicates rich, brownish is correct.

 

Hello there

#6 Plugis dark shade of grey/brownishDefinitely no evidence of white deposits. Hope this helps.

Thank you

[IMG]local://upfiles/19741/4BD8EBF15257466E992CA56353870946.jpg[/IMG]

 

I'd pull some plugs from the other cylinders and compare them to see if they are noticably different. The pic is too dark/fuzzy for me to really see it.

Have you checked your fuel pressure?

 

I have had this same problem - misfire on cylinder 6 in a 2002 MPV. It started about a year ago, replace coil and spark plug, but it came back. Mazda/Ford dealer diagnosed and said it was low compression (i.e. perhaps you should have a compression check?). The car has 112,000 miles, so pulling a head off is too much money. I did a longer drive, used Techron additive, and it went away... for a while. The check engine light does come back on, but the car runs fine. And, then it will go away again. I've pulled the plug recently (did waterpump a month ago), and it was fine. So, fuel and spark are okay. My wife drives this car and does many less than 5 mile trips. I'm thinking that this is an issue with deposits on valves, but it is too expensive to go to the next step. I'm wondering if cylinder 6 is a problem with this engine? We've had this car since new and taken very good and careful care of it (i.e. every service and oil changes done, only family driving, etc). Any thoughts? Frustrated in Maine...