[hogbmw]

So since installing my PBX, around that time period, I am not sure if it was the PBX or just an incidental problem, I have gained a sputter in my engine. Service engine soon light is yellow. It is pretty violent at some times. Some times the engine will run perfectly smooth. When I start the engine up on a cold morning it will near always do this. At idle, it will idle at around 700, the normal idle, and after a few seconds the rpms will to around 400 and it will act like it's dieing then rev a few times causing a shake in the car. It is really frustrating. Most of the time if I pop it in neutral and turn the engine on and off it will fix the problem. In addition, sometimes I will start accelerating and all the sudden the engine will start massively sputtering. The RPM's will not raise without flooring it and they raise extremely slowly. The RPM's juggle about 50 up and down I'll try and take a video next time it happens. The SES light starts flashing on and off. Then sometimes I'll accelerate if I floor it and it'll give a really weird acceleration. The RPMs rise like 500 and then rise acceleration is cut for about the same then it will continue all the way through the powerband.

I took it to the dealer and they instructed to take out the tune, and blamed it on the PBX. My SA said that the PBX ignored the post-cat sensors closest to the exhaust and so the car didn't know what to do since it had different readings. So I took the PBX out and I still have the same problem. It could have a messed up wire down there but I don't think the engine would function at all if that was the case.

Has anyone seen this before? Anyone have any ideas what it may be? It's a 2007 328i e90 CPO with 69k miles and it lasts till 106k or so, so plenty left on warranty. Has a K&N drop-in intake and straight pipes done well(the people at the BMW place complimented the job on the welds). Not sure what it could be! But help would be greatly appreciated. I'm thinking I might should just take it back to the dealership and tell them this what it does without the PBX so it couldn't be the cause.
Thanks to all that read this!

[Hooy]

Dirty MAF sensor?

[E90 87ss]

Why not read the codes first. If nothing makes sense than remove PBX and see if the problem remains...

[hogbmw]

Originally Posted by E90 87ss

Why not read the codes first. If nothing makes sense than remove PBX and see if the problem remains...

I did remove the PBX and check the codes.. that's how I knew there was a misfire. Thanks for the advice. I cleaned out the MAF sensor a few weeks ago when the problem first arose, but It wouldn't hurt to try again. The K&N might have had some oil on it that got on there. I cleared the codes and I'm gonna see which ones pop up as there was 11 of them.

P2243 O2 Sensor reference Voltage Circuit/Open
P2415 O2 Sensor exhaust sample Error
P2629 O2 Sensor pumping current trim circuit/open
P2196 O2 Sensor Signal Stuck Signal Rich
P0305 Cylinder 5 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P0300 Random/Multiple Misfire Detected
P112c Intake Air Sensor 1 Circuit Low
P2415(twice)
P2629(twice)
P2196(twice)

[fdriller9]

Vacuum Leak? Check the PCV lines.

[fdriller9]

I was going to say all those codes are related to the O2 sensors with the except of the misfire codes. But the O2 sensors maybe just fouled because there is fuel on them.

[hogbmw]

Originally Posted by *********

I was going to say all those codes are related to the O2 sensors with the except of the misfire codes. But the O2 sensors maybe just fouled because there is fuel on them.

Which O2 sensor though? Should I clean off the mass air flow sensor again?
Would the misfire codes be O2 sensor related?

[fdriller9]

Originally Posted by hogbmw

Which O2 sensor though? Should I clean off the mass air flow sensor again?
Would the misfire codes be O2 sensor related?

I don't think the MAF has anything to do with this. It won't hurt to clean it though.

I added some info to the codes you provided. Anything after --- is what I added. Also, B = Bank, S = Sensor

P2243 O2 Sensor reference Voltage Circuit/Open --- B1S1
P2415 O2 Sensor exhaust sample Error --- B2S1
P2629 O2 Sensor pumping current trim circuit/open --- B2S1
P2196 O2 Sensor Signal Stuck Signal Rich --- B1S1
P0305 Cylinder 5 Misfire Detected
P0304 Cylinder 4 Misfire Detected
P0300 Random/Multiple Misfire Detected
P112c Intake Air Sensor 1 Circuit Low --- B1S1
P2415(twice)
P2629(twice)
P2196(twice)

The reason why your getting P2415, P2629, and P2196 twice is because your car stored the fault for 2 driving cycles. It just means it's a reoccurring fault.

How long have you been having this issue and how long have you been driving it like this? A misfire means there is no/little combustion of fuel. So that unburnt fuel is going into your exhaust/cats. Unburnt fuel will damage your cats if you don't take car of the situation promptly.

A bad reading from your O2 sensors can cause misfires because the car can't create a proper Air to fuel ratio.

You should have someone else do a proper diag before you replace the O2 sensors on B1S1 and B2S1.

But it looks like both pre-cat O2 sensors are faulty.

But I also think, not 100% on this, that a vacuum leak will cause this too. So have the PCV system looked over. Then move onto the O2 sensors.

[hogbmw]

Okay. Well it was like that maybe a month before I took it in like 2 weeks ago. They had it and replaced the coils and I think they said they replaced an O2 sensor. How would I go about checking vacuum lines? I'll search it up I suppose. I'd like to avoid taking it in cus last time they had it a week n a half and all they could say was it was the tune. So am i correct in assuming that would mean there is too much fuel running into the engine then which would gum up the O2 sensor which would cause it to not be able to read it? Do you think this is caused by the PBX or incidental? HMmmm.


Thank you so much for all your help, btw. I don't know a whole lot about cars and much less intense million sensor german cars.

[AddictedToBavarian]

They didn't void your CPO warranty when they found your PBX?!

[fdriller9]

Originally Posted by hogbmw

Okay. Well it was like that maybe a month before I took it in like 2 weeks ago. They had it and replaced the coils and I think they said they replaced an O2 sensor. How would I go about checking vacuum lines? I'll search it up I suppose. I'd like to avoid taking it in cus last time they had it a week n a half and all they could say was it was the tune. So am i correct in assuming that would mean there is too much fuel running into the engine then which would gum up the O2 sensor which would cause it to not be able to read it? Do you think this is caused by the PBX or incidental? HMmmm.


Thank you so much for all your help, btw. I don't know a whole lot about cars and much less intense million sensor german cars.

This diagram is for a US spec, 06/07 build, N52N 328i....I'm not sure if you have a N51 or N52N.

Check this system out, mainly the hoses.



Here's a blow out of a 325i PCV system.

[DJJG-KWSW]

i had almost the same malfunction as you, but it happened because i did a muffler and resonator delete, put the stock one back on and the car was normal again, i dont know if its because i have the dinan tune, i had misfiring in all the cylinders though

[Hey Ant]

When I first saw your title, I thought it said something like this at first glance:

328: "Knock, knock"
Me: "who's there?"
328: ::Sputter::....::Misfire:: "PBX?"
Me: "I hope everything work out "

[Dr. Nate]

The only way the PBX could possibly damage the O2 sensors is if it was causing the car to run pig rich and the O2 sensors became fouled up. However I doubt this is the cause, plus you didn't mention having bad fuel mileage.

I agree with checking your PVC system.

-Nate