CEL P0306 code thrown after spirited drive above 4k rpm

[ra996tt]

So, since the weather finally got warm I went for a spirited drive on some curvy backroads. Car ran strong and trouble free for the trip there but I pulled out of a stop pretty hard to the left and drifted the car a little. A few yards after that, boosting out of left slight bank turn, I get a CEL code flashing and goes away. P0306 Cylinder 6 misfire, and only happens after 3500-4000 rpm under half throttle or more. Reading forums on here suggests coilpacks, plugs. Car has EPL flash but everything else is stock. Coilpacks and plugs were changed not too long ago. Bad plug? Coilpacks? Should I switch the coilpack to cyl 5 and ddrive around or just replace both coil and plug and cross my fingers? Thanks in advance

[Loren]

:welcome:

That is the correct diagnosis and troubleshooting. Likely the coil pack but a bad (or loose) plug will also act that way. Do the coil pack swap and see.

[jpflip]

There is a note in the OBDII manual :

In the event of a short circuit to B+ or ground in the oxygen sensors

ahead of the TWC, the mixture becomes too lean or too

rich. This can cause misfiring. If, in addition, an oxygen sensor

signal fault ahead of the TWC is stored in memory, first correct

this fault and then road test the vehicle.

Erase and try again....

Edited April 24, 2011 by jpflip

[ra996tt]

I did this several times and it's P0306 every time. Going to switch out the coilpack to cyl 5 and see if it follows.

There is a note in the OBDII manual :

In the event of a short circuit to B+ or ground in the oxygen sensors

ahead of the TWC, the mixture becomes too lean or too

rich. This can cause misfiring. If, in addition, an oxygen sensor

signal fault ahead of the TWC is stored in memory, first correct

this fault and then road test the vehicle.

Erase and try again....

[jpflip]

There is no better way to found out. Good luck!

[ra996tt]

There is no better way to found out. Good luck!

Cyl 6 is passenger side farthest from the front bumper correct? Hopefully I am wrong in this and it's on the driver's side because I replaced spark plug, switched coil pack from 6-5 (If my numbering is right) and went for a drive, CEL still came on the 6th cylinder. Unless it's the driver's side farthest from front, I will have to take it in :(

[Loren]

Cyl 6 is passenger side farthest from the front bumper correct?

Correct.

[ra996tt]

Cyl 6 is passenger side farthest from the front bumper correct?

Correct.

I'm confused though :( This diagram shows me something different...

Got it from pelican parts website...

http://www.pelicanparts.com/techarticles/911_static_timing/911_static_timing.htm

Edited April 25, 2011 by ra996tt

[jpflip]

Then I am confused too. I always thought it was the one in front right side....????? Always used the diagram you are showing....

Edited April 26, 2011 by jpflip

[Loren]

That diagram shows the same layout - the arrow is pointing to the front of the car.

So as you face the engine compartment the 4-5-6 are on the passenger side.

[jpflip]

That diagram shows the same layout - the arrow is pointing to the front of the car.

So as you face the engine compartment the 4-5-6 are on the passenger side.

But Loren, #6 cylinder is the closest from the front bumper not the farthest like mention in the sixth post, isn't it?

[Loren]

That diagram shows the same layout - the arrow is pointing to the front of the car.

So as you face the engine compartment the 4-5-6 are on the passenger side.

But Loren, #6 cylinder is the closest from the front bumper not the farthest like mention in the sixth post, isn't it?

No, the flywheel faces the front of the car.

Carrera, GT2, GT3, and TT are rear engine cars - that is, the engine faces rearward.

[ra996tt]

That diagram shows the same layout - the arrow is pointing to the front of the car.

So as you face the engine compartment the 4-5-6 are on the passenger side.

But Loren, #6 cylinder is the closest from the front bumper not the farthest like mention in the sixth post, isn't it?

No, the flywheel faces the front of the car.

Carrera, GT2, GT3, and TT are rear engine cars - that is, the engine faces rearward.

Either way I read it wrong. The #6 cylinder is the closest to the front bumper on the passenger side. Switched coilpack to #5, repalced spark plug on #6 and went for a drive. Threw CEL P0305, misfire on cyl #5. Coilpack going in today and hopefully I'll be all set. On a side note, Tony from EPL recommends against the platinum NGK's for turbo applications. He instead recommended BOSCH FR6-LDC, looks like I will be replacing all plugs in the near future. Thanks to this site's DIY I have now saved $1600 in labor from the dealership and knowing it's done right. Thank you renntech! :)

[Loren]

Have a look at the rest of the coil packs - if they have cracks I would replace then too.

[ra996tt]

Have a look at the rest of the coil packs - if they have cracks I would replace then too.

Previous owner replaced all coilpacks very recently. I sure do hope they don't have cracks :(

[Sunnyside]

Cyl 6 is passenger side farthest from the front bumper correct?

Correct.

I'm confused though :( This diagram shows me something different...

Got it from pelican parts website...

http://www.pelicanparts.com/techarticles/911_static_timing/911_static_timing.htm

This is Correct.

[Sunnyside]

What did you set the plug gaps too. ??

[ra996tt]

What did you set the plug gaps too. ??

The plugs on the car currently are platinum plugs which are 4 prong ngk plugs that didn't need gapping. Will be using FR6-LDC as per Tony at EPL since he's the tuner for my car. Replacing all 6 plugs and that one coilpack and others if they are cracked. Hopefully car will run strong :)