After resolving some ignition coil issues, I'm getting the following codes:

29e0 - fuel mixture control
2d06 - air mass system
29e1 - fuel mixture control 2
6e83 - tire pressure monitoring systems invalid


Could this still be linked to the coils? When I'm driving at low-rpm and coming to a stop, the engine wants to turn off and sometimes does. I recently cleaned (but did not replace) my pre-cat o2 sensors. I'm so confused as to what this could be. The MAF sensor is not supposed to go bad.

I'm thinking it could be a number of things:

1.MAF sensor
2. Battery (even though I had battery tested a month ago and shop said it was at 84% life left)
3. o2 sensors
4. Plugs? --- 2 plugs are brand new....4 plugs are 30k old.
5. Vacuum leak? -- how do i properly check for one?
6. Something else? (suggestions please)

 

It seems to me something is unplugged. check your coils again. Why would you change 2 plugs versus all 6. Your MAF can be unplugged and you can drive the car. You would just burn more fuel. So that is not your issue. You either have a coil, injector or plug issue. What brand coil did you get? Hold on did you say you cleaned the 02 sensor? YOu may have ruined it

 

I'd recently changed all 6 but two were failing so I changed those 2. The other four were not giving error.

I gently cleaned the two pre-cat o2 sensors and their error codes disappeared. Could the fuel mixture code be due to bad injectors?

Car runs fine at RPM above 1200, but once you get close to a stop and get down to 1000 it quickly drops to 600 and wants to turn off unless I tap the gas again.

 

Yes it could be he injectors. I would troubleshoot from coils to injectors. Unplug your coils one by one at idle to see if it the coil or plug on that cylinder. If that passes move to the injectors. Do you clean your fuel system regularly. Have you taken the injectors out and cleaned them. I'm real positive your issue is with the injectors or coil. What kind of plugs are you using? You shouldn't have to mess with them for 70k - 100k miles depending on your preference. Do not cut cost with parts on a BMW because you will pay in the long run. If the part makes the car run then go OE.

 

I will try that with the coils. I have never really cleaned my injectors.

My coils are brand new Bosch coils and the spark plugs are also Bosch. 4 of 6 spark plugs have 30k on then and 2 are brand new.

 

I only have two codes left at this point.

29D0 - Misfire cylinder 4
2D06 - Air Mass System

I'm going to replace the coil in 4 (which was new) but how do I deal with 2D06? I used mass air flow sensor cleaner on it to no avail. The error still comes up after cleaning. Is it my sensor? Car has 93,000.

 

What did you do to get the other codes cleared? I would clear the codes and switch the coil to another cylinder to see if the problem moves first before getting another coil. With the MAF there is a possibility it is bad. If you feel like you have done everything (cleaned connector, MAF and made sure it is plugged in correctly) then just replace it with an OE part. This is one item you will need it to be a Siemens/VDO (preferred) or continental.

 

I'm going to change all of Bosch coils to brand new Delphi and change the MAF.

Is it really worth paying the extra $60 for Siemens over Spectra?

 

To me it is. I just know people who have bought OEM MAFs have had a lot of issues. Most have ended up returning and getting OE (the ones with the part still warranted). If you want to try it go ahead. I have never had to replace mine just read threads with stories. If you go OEM make sure it has a good warranty or you will be out of money. The number one complaint is fluctuating RPMs

 

I've replaced all coils and will replace MAF on Wednesday. I'm still getting the following codes, which partly befuddles me:

29D0 - Misfire cylinder 4 -----------third new coil on this cylinder ---spark plug is also new.
2D06 - air mass system

6e83 - tire pressure monitoring systems invalid
9c55 - fogging vapor sensor
E18F - Central registry does not match with debit configuration

Note, I've also unplugged one of the two sensors on the left cabin air filter (the hood sensor) because it was malfunctioning. But I don't think this has anything to do with my issues.

What could continue to cause the misfire? The MAF?