2004 CTT - Engine misfiring - runnning a tad rough

[slaskowski]

I bought a 2004 CTT about 18 months with the CPO warranty from the Porsche dealer. It now has about 50K miles on her, been a great car, love the acceleration and solid feel. Been pretty much trouble free until about a month ago when it started running a bit rough and the check engine light came on. The roughness comes and goes but has been more prevelent recently. I ended up buying a Durametric enthusiast kit directly from Durametric (about $300 USD). I checked the codes today and got the following:

P0356

P0300

P0305

I cleared out the codes (probably a stupid idea prior to taking it to the dealer) and when I started it back up the engine light did not come back on.

I am going to take it to my dealership on Friday as it is still under warranty, though I am concerned that it might not be covered under the CPO program. A couple of quick questions for you smart guys:

- Any idea what the problem could be based on the codes and symptoms?

- Gut on whether it will be covered under warranty?

- I was going to drive her about 225 miles to Baltimore for the holiday weekend. Is there any chance of doing any long term damage to the engine?

Thanks in advance and i hope that all of you and your families have a wonderful Thanksgiving - Steve

[Loren]

P0356 Bar ignition module on cylinder 6

P0305 Cylinder 5 Misfire Detected

P0300 Misfire detection - checksum error

Multiple misfires - most likely the ignition coil packs. A common TSB noted issue.

Have them replace them all with the latest version - or save some money and do it yourself.

[slaskowski]

P0356 Bar ignition module on cylinder 6

P0305 Cylinder 5 Misfire Detected

P0300 Misfire detection - checksum error

Multiple misfires - most likely the ignition coil packs. A common TSB noted issue.

Have them replace them all with the latest version - or save some money and do it yourself.

Loren - Thanks for the super fast reply. Would you know if it is covered under the CPO warrantee? Hope that you and your family have a great holiday.

[Loren]

The TSB says it is free to those under warranty. All you can do is ask them.

If not, as I said it is not that hard to replace them yourself. The coil packs themselves are only about $20 each (MSRP) so even cheaper from Sunset Imports.

[slaskowski]

P0356 Bar ignition module on cylinder 6

P0305 Cylinder 5 Misfire Detected

P0300 Misfire detection - checksum error

Multiple misfires - most likely the ignition coil packs. A common TSB noted issue.

Have them replace them all with the latest version - or save some money and do it yourself.

Loren - Thanks for the super fast reply. Would you know if it is covered under the CPO warrantee? Hope that you and your family have a great holiday.

Also any recommendations on whether to buy genuine Porsche parts or aftermarket in this case? Also any recommendations on places to buy them from in which you (or thers) have had good experiences with?

[Loren]

I would use factory latest parts since these have been problematic. Order 948.602.104.05 US MSRP $19.54 each. These are the latest parts from Porsche.

I would order from Sunset Imports (Porsche Parts at Dealer Cost) for much better pricing and great service for RennTech.org members.

[wvicary]

Might consider replacing the spark plugs at the same time as they can be damaged from a misfiring coil.

[paulmurph73]

Hi I have 04 4.5s with same problem canyou tell me how much the replacement ptrs

Cost and wether the job can be done easily

Do you feel the durametric is worth the money

Did you consider changing air flow mass meters or did the plugs

And coil change fix the problem

Thanks

Paul

[slaskowski]

I would use factory latest parts since these have been problematic. Order 948.602.104.05 US MSRP $19.54 each. These are the latest parts from Porsche.

I would order from Sunset Imports (Porsche Parts at Dealer Cost) for much better pricing and great service for RennTech.org members.

Loren - Thanks for all of your help. The dealer ended up replacing all the ignition coils under the CPO warranty. The warranty is up in May so it looks like I may have to start doing some of these things myself :)

[slaskowski]

Hi I have 04 4.5s with same problem canyou tell me how much the replacement ptrs

Cost and wether the job can be done easily

Do you feel the durametric is worth the money

Did you consider changing air flow mass meters or did the plugs

And coil change fix the problem

Thanks

Paul

Paul - I am not sure about your other questions as they are out of my areas of expertise, however I would highly recommend getting a Durametric. It is easy to use and the information that it gives you will ehlp you with the following:

- When posting to Reentech, it will give the smart guys (and there are plenty of them here) the detailed informaiton that they require to offer you detailed rememdies (as you can see from the above posts). Otherwise wiithout the codes it becomes very difficult to debug and I immagine that the quality of your replies may be less than ideal.

- It will help keep your dealer/mechanic "honest" as I find that if you go in with some knowledge of the problem they are less likely to treat you like a moron or worse case start playing "replace the part" game. I also keep my unit in the car in case I ever have a problem while traveling.

- $300 is not cheap, however if you figure that you will be keeping your Porsche for a few years, it will pay for itself many times over

Good luck - Steve