EvanMitch

Hey guys this is my first post on here so here it goes. Im driving back from a friends house tonight and my cars been running fine all day (Floyd Bennet Field airstrips were a ghost town today) I was on it today pretty hard for a while and tonight the cars exhaust became deeper of all of sudden and my CEL comes on. I need some insight on what the codes mean and how i should go about fixing my baby. (its a 535i xdrive 2010 with a cobb tune and injen intake with a muffler delete)

EvanMitch

the codes are as follows

KyleB

Try looking those codes up in Google; i.e. "BMW P29CD"

I did, and it looks like they're basically a bunch of misfire codes.

tonyb635

Not sure about the first code but the next two show a misfire. Probably spark plugs or a coil. If your plugs are old, maybe more than 30K I would change them. If they are not old, maybe just change the two. When doing this, you can swap the coil packs E.G. 1&2 and 3&4, just so that each of the detected cyl get a coil pack from a cyl that is not showing a problem. Run the car and see if these codes change or problem is better. Sorry, can't help you with the over voltage and I am confused why the car would get louder...

2DEB Power Mgt Overvoltage
29CD Cyl 1 Misfire detected
29CF Cyl 3 Misfire detected
29CC Cyl Misfire, Several Cyl

EvanMitch

it didnt get louder i said it got much deeper then usual

EvanMitch

Cars on the truck now going to the stealer ship to get this HPFP sorted out once and for all (this is the fourth problem with this even after i paid for there injector cleaning service)

tonyb635

So your HPFP also went out? There is a pretty clear code for that one.

jcolley

DME will shut down cylinders which have misfired by shutting down the injector and spark. That is likely why the sound changed.

I just had an injector stick open and hydro-lock the engine. 5 weeks of working on it and sent out all injectors for cleaning/testing. 1 additional found "unreliable" and the others returned. Fired it up for the first time Saturday and a completely different injector stuck open on the same cylinder. One of the injectors I just had tested failed. They are pricy, but I will replace them all vice cleaning if I have any more problems with them.

If an injector failed open, do not let them just change the injector and call it good. There is a good chance that the cylinder wall was washed down an potentiall scored by unlubricated piston rings or a connecting rod bent due to trying to compress a fluid. At a bare minimum, boroscope the cylinder through the spark plug hole and drop the oil pan to check the rods.

If you are under warranty, let them do as they please, but if not it can get pricy quick if the engine is damaged due to insufficient investigation.