Hey Guys, I'm really puzzled here.
My 08 535xi run perfectly fine if I take out the Cobb AP map and flash it back to the stock but if I put a stage 1 flash on the car and if I try to get the rpm above 3k then the engine light comes on and car starts shaking really bad.

The below 2 codes also comes on when the car is jerking but the strange thing is if I use the AP to reset the codes then car stops jerking right away unless I step on the paddle and go above 3K rpm.
P0306
P29D2

The strange thing is if I uninstall the AP, no matter how I floor the car I don't get the engine codes above and no jerking.

Can anyone please help me out? I uninstalled the flash and took the car to the dealer with no error codes telling them to look at cylinder 6 but they won't because "there is no error on the system."

 

Those are misfire codes for cyl 6. How many miles does the car have? To troubleshoot swap your coils to see if the misfire travels to the cyl you swapped the coil from. If it does then get a new coil, imo I'd just replace all 6 as preventive maintenance. If the misfire stays on 6 then replace your plugs. If you haven't replaced your plugs for the last 30-40k miles I'd venture to say your plugs are going.

 

ECS makes a kit with new plugs and coils. I highly recommend it.

BMW E61 535xi N54 3.0L ECS News BMW E60/61 5 Series N54 Ignition Service Kit

 

Car currently has 67K miles on it, dealer just changed the coil and plugs about 4 months ago. And I've been riding without the AP since then because of the jerking.

 

I'd actually look at the paperwork the dealer gave you to verify the coils were replaced. BMW will usually only replace plugs at 45-50k mile mark. Coils are usually not replaced unless there is a misfire issue that isn't solved by changing out plugs. BMW looks at coils as a 100k mile replacement item.

 

yea i had an misfire before and they replaced the coils with the plugs.

 

Well if that is the case then the two other probable causes are a faulty injector or carbon buildup on the intake.

 

Aren't we forgetting the obvious? The Cobb AP is probably the culprit. It is not communicating properly with the car computer. Everything runs fine without the AP, so chasing plugs, coils, injectors etc. is futile since the engine runs fine without the AP.

Salut, Bob P.

 

No it isn't the AP. The map that is flashed to the DME from the AP is adding more requested power out of the engine. Even though stg1 maps are a mild increase it is a increase over stock that can and will expose any weakness in the engines ability to produce the requested power.

OP- just curious what stg1 map are you flashing; drive, sport or aggr? Also what fuel are you using 91 or 93 oct and what brand of gas.

 

I would start with Booyaazaa's original suggestion of swapping #6 coil pack with another one to see f the issue follows the coil pack or stays in cylinder 6. It is the easiest and least expensive first step for a misfire.


I'm curious: Does the car pop up the codes with the Cobb installed even when you gently accelerate up to and past 3,000 RPM?