garthed

I just purchased a 2005 Carrera s. it has about 60k on it and the motor was replaced in 08 with 30k miles on the car. I purchased it in Denver and drove it home to California. It's been great until this weekend that I got a solid check engine light. I read the codes and getting random miss fire code and 1 5 and 6 cylinder misfire. I cleared them out and they did not come back for a few days. It appears to happen on cold starts. I can here a slight miss fire right at start up. Just a subtle popping then goes away. It runs and drives fine. I'm totally freaked out. Taking it to a local dealer tomorrow. Do you guys have any ideas? This is my first Porsche and not sure what is normal for these cars.

Thanks
Garth

becauseitis

probably the coil packs. it happened to me. replaced them all with new plugs and all good.

Petza914

Since you have misfires on both cylinder banks, that's a clue. Could be plugs and coil packs at 60k miles if they've never been done or could be some other things. Is the air intake, filter, and exhaust stock or aftermarket. If aftermarket, is it running cats or cat bypass pipes - if cats, 100 cell or 200 cell?

If an oiled filter type intake, the oil from the filter could have dirtied the Mass Air Flow Sensor (MAF) and it needs to be cleaned or replaced.

garthed

The car is all stock. No mods other then wheels and springs.

JuanK20

Definitely change the coil packs and plugs.

Blaine 997

First off, welcome to Porsche ownership!

You car and situation are very similar to mine. I got my 05 C2 the last week of November 2016 from FL. This is my first 911. IMS failure took out the original engine at 20,000 miles in 2008, replaced by Porsche under warentee. Now the car now has 55,000 miles. The PPI said the coil packs were cracked but where not causing any problems yet. The second time I drove the car, it had the same symptoms you are reporting. New coil packs and plugs solved the problem.

garthed

Ok cool. I hope its the same thing for me.

SoCal C2S

I will agree on the coil packs.....but, just thinking outside the box (and with little info), the car came from Denver (high altitude) and now is in CA. Is there an ECU update that's needed?

My car came from FL and when it first came to CA it failed smog due to a misfire.....then they loaded new ECU software and then no misfire/passed smog. The existing code was from the factory as my first thought was it had a tune or something but that was not the case....

but it's probably the coils.

garthed

I took the car to the local Porsche dealer. They could not get the car to backfire again. It was already warmed up. They did say the coils looked good and to just drive it. They said if it was the coils they will get worse and then will be a good time to replace. They over all did not seam to concerned.

I asked about the elevation difference too. They said that the car would change automatically for the air at sea level.

Unrelated they said I should change my pulleys.

SoCal C2S

It was a long shot although mine went from sea level to sea level...probably completely unrelated.

Hope it sorts itself...sounds like the dealer gave you firm direction to drive it!

garthed

Not to hijack my own thread. Socal C2S where did you get your wing?