[Powaup]

Hi, I just finished installing an N55 JB4 EWG to my rwd 8zf m235i along with a VRSF catless downpipe, after taking the car out for a test drive the car starting jerking after a going WOT, the car basically started jerking on and off and kept throwing Drive Train Malfunction codes so I drove back home, unfortunately I was unable to data log since I can not do WOT pulls.

I then updated the firmware of the Jb4 and went for a ready and saw no issues whatsoever, unfortunately was unable to data log during that ride as the cable wasn't tight enough to the unit.

Parked, washed the car and tried to drive again (15mins later) but now the "coughing" is back like crazy. Seems like as soon as I put my car in reverse the car starts acting up like crazy and throwing drive train malfunction codes

I tried map 0 and the car still shakes/stutters like hell, soon as I put in reverse it throws an engine malfunction sign


PS: had an s55JB4 on my M4 and did not experience any issue like this with that tune

I've read that this can happen when running map 2 on 91 octane however I was running Map1.


Any help fixing this issue would be appreciated, starting to wonder if the problem could be related to the Downpipe instead of the tune...

[228]

See if your dp is installed correctly

[Powaup]

OBD2 diagnostics is saying code P0192 is the culprit for the drivetrain malfunction

[Amack]

take the JB off and see how it runs without it perhaps?

[Benandluna]

yeah dude. Do this. See if its the cat or the JB. I dont see why a cat would do this if installed right beside throwing a CEL. if the car is fine id call burger. Though it seems like you arent the only one experiencing issues with a JB tune currently if u look at the forums.

Who installed the JB. the first general question is did they install it with the battery disconnected.

[Powaup]

Originally Posted by Amack

take the JB off and see how it runs without it perhaps?

Originally Posted by Benandluna

yeah dude. Do this. See if its the cat or the JB. I dont see why a cat would do this if installed right beside throwing a CEL. if the car is fine id call burger. Though it seems like you arent the only one experiencing issues with a JB tune currently if u look at the forums.

Who installed the JB. the first general question is did they install it with the battery disconnected.

So it turns out the problem is related to the JB4 unit, I bought a used JB4 from someone that had one of the early versions and upgraded it himself to the newer version, I removed all connections except for the TMAP and OBD2 sensor and the car is fine except from CEL popping up at times which is probably due to the catless DP.

The whole point of the JB4 was to keep the CEL from the DP from popping up so I will probably send the JB4 to Terry for him to fix the unit and then I should be good.

On a side note: I'm not sure how I feel about the Catless DP, it makes the car sound 35% better but the smell of gas when parking is kind of annoying.

[Powaup]

here's the thread on N54tech if anyone is interested http://www.n54tech.com/forums/showthread.php?t=46450

[Amack]

Originally Posted by Powaup

So it turns out the problem is related to the JB4 unit, I bought a used JB4 from someone that had one of the early versions and upgraded it himself to the newer version, I removed all connections except for the TMAP and OBD2 sensor and the car is fine except from CEL popping up at times which is probably due to the catless DP.

The whole point of the JB4 was to keep the CEL from the DP from popping up so I will probably send the JB4 to Terry for him to fix the unit and then I should be good.

On a side note: I'm not sure how I feel about the Catless DP, it makes the car sound 35% better but the smell of gas when parking is kind of annoying.

I have a catless dp. the gas smell is very noticeable. I would worry about it tho the gains should out way the smell

[mike@x-ph.com]

Glad you got it figured out OP

It is always helpful to mention any parts that were bought used when posting about issues with the car.