JB4 Malfunction! HELP

[skiz135i]

Hey everybody. Thanks again for taking the time out to help me!!

OK - so I have an 09 BMW 135i 6MT.. Car CURRENTLY has BMS cone filter intake, BMS catless downpipes, berks axleback (pro), active autowerke chargepipe + bov, and JB4. The car ran fantastic when I was running just the intake and JB4, but as soon as I installed the downpipes it started running strange Obviously the car throws codes for the cats, but under WOT it continues to shoot me from map 5 to map 4. It is also a bit choppy at low RPM - as I'm lightly pressing down on the throttle there is a studder between like 2k-4k RPM.

I've read a lot online and people have said the car could be misfiring, and even after diagnosing the CEL and finding out that it was not throwing a misfire code, I still went ahead and changed all plugs.. all stock coil packs seem to be working properly but I was going to change them also as another precautionary measure.

I've tried resetting the JB4 and sometimes that prolongs it kicking me from map 5 to 4 for an extra few minutes, but it inevitably sends me to 4 from whatever map I'm running (I've also tried running map 2 instead and it does the same thing)

Is this a common issue?

Please let me know what I can do to diagnose the source of this problem!!

Thanks again for your help!!

[skiz135i]

Any ideas?

[mike@x-ph.com]

You probably did not install the Oxygen sensors correctly.
This is a very common mistake when installing downpipes. Double check your O2 sensors.

[MuNkY6913]

Originally Posted by mike@x-ph.com

You probably did not install the Oxygen sensors correctly.
This is a very common mistake when installing downpipes. Double check your O2 sensors.

Had the same thing happen to me. Chased misfires all summer. Installed the rear o2 sensors in the wrong pipe. Car will run with those switched. Won't run with the front switched. The video i watched had them switched too. Gray sensors go in one pipe and black sensors go in the other. Just match the rear ones with the front ones color. hope that solves your problem. For future reference posting a screen shot or list of codes thrown would be helpful. You should come up to mpact this weekend. Should be sweet. There's a thread in our region. http://www.1addicts.com/forums/showthread.php?t=1144103
Www.mpacteast.com

[skiz135i]

Ok so I switched the 02 sensors bc they were in the wrong place and it still sends me to map 4.. Very frustrating. Any other reason why this could be happening?

[mike@x-ph.com]

Originally Posted by skiz135i

Ok so I switched the 02 sensors bc they were in the wrong place and it still sends me to map 4.. Very frustrating. Any other reason why this could be happening?

Now we need the codes and logs if possible