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      11-10-2012, 01:17 AM   #1
Second Lieutenant

Drives: YMB F82 M4
Join Date: Feb 2012
Location: United States

iTrader: (2)

Diagnosing problems after DP's

I've been having this issue for some time now and I am in dire need of suggestions. I had JB4 installed and running well for several months on map 1. I installed VRSF catless DP's and began to run map 2. It ran perfectly for a few weeks, then I started to get codes, "service engine soon" light and sometimes "limp mode." Also, sometimes the car seems to stutter, as in jerk back and forth slightly as I am casually driving down the road. After it starts to act up, it is much more likely to continue to act up (After I clear the codes, it tends to run well for a while). Part of this includes a weird idle, it will randomly climb and then slowly fall back in place, sometimes rather roughly. I tried using map 2 and taking it easy, but still have issues. I ran map 1, same problem. I tried leaving it on stock map and it seems to be less likely to act up but still had the "service engine soon" light the other day just driving down the highway. I've replaced both pre-cat o2 sensors and the hpfp within the last month because I was getting those codes. I am still getting the same codes. One of the problems is that it doesn't always happen, some days it will be fine. I took it to BMW because finally the problem seemed to be occurring on stock map, leading me to think it was a hardware issue and not a tuning issue. I asked them to test my fuel pressure regulator because I was thinking it may be running rich. They said its within spec at 5.5 bar. Also, they blame it on the JB4.

The most likely situation in which limp mode occurs (big check engine light comes on and cuts all power) is when I wind out 3rd or 4th, not 2nd.

This picture is of the codes I'm talking about, it has been the same codes almost every time I check (mostly running map 2):

This is the picture of the scan done at BMW, these are codes that came up while I drove stock map only:

Mods are BMS DCI, OCC, JB4, VRSF DP's.

I am so frustrated and basically out of ideas... Anybody have any suggestions? :