Misfire nightmare! Pleeease help!!!

I had to have an engine swap after blowing the head gasket on my '02 325i. So after about a month of looking I found an entire '05 engine w just under 60k on it. Everything on it looked great, very clean and well taken care of. Was told it had a compression test done, and ran great. Everything on the engine was exactly the same as on the original with the exception of the ignition coils (new one has the updated, non-bolt down coils and old one had bolt down) and one plug on the wiring harness (old engine had rounded plug, new one had square- only a positive and neg wire for the ignition harness).

Anyways, I've got the motor swap done and everything installed. Started up the engine and am getting Misfire Cylinder With Fuel Cut-off on all cylinders except #2. So we replaced all of the spark plugs and cleared the codes. Still same thing. Next went on to swap the fuel rail, same thing.

Do you think I need to have the car flashed since it has the updated ignition coils?

Last week I swapped out the maf and it helped, but it's still misfiring and flashing codes. I did unplug the the old maf and it actually started to run better (so the maf was def bad). Installed the new one and unplugged it and the car nearly dies. So maf, check. With the new maf in, the car is running much better and isn't going into valet/limp home mode. So that's good, but its still popping up codes. Some different ones now though:
P0174 System too Lean (Bank 2)
P0172 System too Rich (Bank 1)
P0300 Random/Multiple Cylinder Misfire Detected
P1083 Fuel Control Mixture Lean (Bank 1 Sensor 1)
P1086 Fuel Control Mixture Rich (Bank 2 Sensor 1)
P1345 Misfire Cylinder 2 With Fuel Cut-off
P1347 Misfire Cylinder 3 With Fuel Cut-off
P1349 Misfire Cylinder 4 With Fuel Cut-off

Here is a link to the original thread: http://forum.e46fanatics.com/showthr...405&highlight=


PLEEEEEEEEEEEESE HELP!!!

It could need to be flashed, but before you try that, have you tried running the old coils?

Originally Posted by Andrew@FCP

It could need to be flashed, but before you try that, have you tried running the old coils?

That's the only thing I haven't tried. The main reason is because to run the old coils, I'd have to swap the valve cover, ignition wiring harness as well as the coils too. The coils on the new engine are the pop outs and the old ones are the bolt down style. That's why everything needs to be swapped in order to put those on. We have tested all of the coils though, and they are all good.

Any idea if a flash will update the computer to communicate with the new coils? Is there any differences between the way the two types of coils talk to the computer? I've seen the wiring schematics and they look identical. Urgh

Here are some of the other things we have tried:
•Swapped the fuel rail and injectors
•Smoked out the vacuum system and found no leaks
•Replaced the MAF
•Replaced the spark plugs

I have decided to swap the valve cover, ignition coils & wiring harness before I bring it into the shop. I'll keep everyone posted...

thats a lot of work to keep that car, i would do the same for mine though

I would like to hear if it worked out for you. Please, post when you get a chance.

thanks

Waiting on a valve cover gasket...bump

your front and/or rear O2 sensors are probably plugged in backwards. This is very common after an engine swap. I just went through this exact same problem on a 2001 engine swap and had very similar codes. The shop I use couldn't figure it out and actually called me for advice. I brought my computer down to their shop and discovered the front O2 sensors were plugged in backwards as bank 1 and bank 2 have identical connectors. They had tried swapping ignition coils, etc. to no avail.

You need to follow the O2 sensor wires and make sure they are connected properly or find someone with a GT1 because it has a test that can be ran to verify that they are plugged in correctly.

Originally Posted by iansanderson

your front and/or rear O2 sensors are probably plugged in backwards. This is very common after an engine swap. I just went through this exact same problem on a 2001 engine swap and had very similar codes. The shop I use couldn't figure it out and actually called me for advice. I brought my computer down to their shop and discovered the front O2 sensors were plugged in backwards as bank 1 and bank 2 have identical connectors. They had tried swapping ignition coils, etc. to no avail.

You need to follow the O2 sensor wires and make sure they are connected properly or find someone with a GT1 because it has a test that can be ran to verify that they are plugged in correctly.

Are you saying that that O2 sensors are switched or that the connectors are switched around?

Originally Posted by iansanderson

your front and/or rear O2 sensors are probably plugged in backwards. This is very common after an engine swap. I just went through this exact same problem on a 2001 engine swap and had very similar codes. The shop I use couldn't figure it out and actually called me for advice. I brought my computer down to their shop and discovered the front O2 sensors were plugged in backwards as bank 1 and bank 2 have identical connectors. They had tried swapping ignition coils, etc. to no avail.

You need to follow the O2 sensor wires and make sure they are connected properly or find someone with a GT1 because it has a test that can be ran to verify that they are plugged in correctly.

I just checked the 2 connectors and they are plugged into the correct sensor. Pretty sure both of those O2 sensors are the same, but if you know different please let me know...

Gaskets just showed up- and we are doing the swap tonight. I'll let ya know what happens...

Well tonight we swapped over the valve cover, ignition coils, and harness... same thing still happening. Anyone have any other ideas??

Originally Posted by iansanderson

your front and/or rear O2 sensors are probably plugged in backwards. This is very common after an engine swap. I just went through this exact same problem on a 2001 engine swap and had very similar codes. The shop I use couldn't figure it out and actually called me for advice. I brought my computer down to their shop and discovered the front O2 sensors were plugged in backwards as bank 1 and bank 2 have identical connectors. They had tried swapping ignition coils, etc. to no avail.

You need to follow the O2 sensor wires and make sure they are connected properly or find someone with a GT1 because it has a test that can be ran to verify that they are plugged in correctly.

o2 sensors read from certain banks as this states. had this issue with my car when i installed ebay headers. swap the front two plugs(since they're the same connectors) and it should fix your problem. trust me. i installed new plugs and was about to do new coils when i searched/asked a few people. rear o2's don't matter really...its the front two that are a *****

Originally Posted by BMWh0r3

o2 sensors read from certain banks as this states. had this issue with my car when i installed ebay headers. swap the front two plugs(since they're the same connectors) and it should fix your problem. trust me. i installed new plugs and was about to do new coils when i searched/asked a few people. rear o2's don't matter really...its the front two that are a *****

I CANT EVEN FRICKEN BELIEVE IT!!
T-H-A-T W-O-R-K-E-D!!

iansanderson & BMWh0r3
You two are sooooo AWESOME!! You have no idea how frustrated I've been with this over the last month+ AND ALL I NEEDED TO DO WAS SWAP THE O2s URGH, Crazy?!

Originally Posted by BMWh0r3

o2 sensors read from certain banks as this states. had this issue with my car when i installed ebay headers. swap the front two plugs(since they're the same connectors) and it should fix your problem. trust me. i installed new plugs and was about to do new coils when i searched/asked a few people. rear o2's don't matter really...its the front two that are a *****

Quick couple questions on your ebay headers...
Did you notice the power increase? Noticeable change in exhaust volume/sound? Was it worth the $ and pain in the a$$?

Originally Posted by tha ridla

Quick couple questions on your ebay headers...
Did you notice the power increase? Noticeable change in exhaust volume/sound? Was it worth the $ and pain in the a$$?

i dont have ebay headers but from what ive seen is yea you feel the diffrence for sure and sound is alot louder..yea its a PITA but i thnk its worth it..

Originally Posted by tha ridla

Quick couple questions on your ebay headers...
Did you notice the power increase? Noticeable change in exhaust volume/sound? Was it worth the $ and pain in the a$$?

lol..i just replied to you in pm but i'll respond without the long story here. low end power loss(typical) but definate high end gain. exhaust...well..i went with the "kpeng" exhaust...so its extremely loud. i love it as my wife won't drive the car now...and the added bonus of pissing off a certain neighbor at 2AM is great. worth every penny to me obviously. but a pain in the ass to install (even though i didn't install them myself..you will probably like to read the pm). advice though is to buy from the suggested ebay sellers. i went with one that wasn't suggested on a spur of the moment purchase. i was sent the correct headers but the one was approx 1 inch longer than the other and i couldn't just bolt up my exhaust.