[awesome82]

Current Mods

JB4 G5 board
DCI
Catless downpipe
Muffler delete
Charge Pipe w BOV

So i have a local muffler shop install my Catless downpipe and when they did they crossed the O2 sensors. as may of you know the car throws a code and starts running incredibly rough with this

I had the o2 sensors put back correctly and the car still doesnt run right ONLY WITH THE JB4 (any map it does the same thing)

with the JB4 off, the car runs great (throws a CEL i am assuming bc the catless dp) but runs great, slow but great

As soon as i up the JB4 on the CELS go away, and once the car goes into full boost, the car starts shaking and throws another cel. This happens on any map

Any ideas?

the car is at TKX currently and they are waiting for someone to come down and read the code

[MrRetep]

the JB4 can be used to read the codes. maybe a misfire?

[awesome82]

Originally Posted by MrRetep

the JB4 can be used to read the codes. maybe a misfire?

i was thinking the same thing.. I guess i will have 2 call them tomorrow

I would think they would know that

[AK 335i]

[Exzackt]

Definitely sounds like a misfire.. When adding lbs of boost, parts that would often need to be replaced, because they were already on their way out. Try spark plugs first. Then ignition coils. If neither of these two then high pressure fuel pump or injectors. How smooth does your car idle? If rough than you might want to clean your intake valves.

[CHECKERED]

I would like some clarification,
- The car had a JB4 installed and was running ok
-after downpipes install with incorrect O2’s runs bad
-O2 sensors corrected but still runs bad (how was it discovered that the O2 sensors were switched, it’s possible they were damaged and now need replacement)

You might need to do a hard rest of the DME by unplugging the battery overnight

[awesome82]

Originally Posted by CHECKERED

I would like some clarification,
- The car had a JB4 installed and was running ok
-after downpipes install with incorrect O2’s runs bad
-O2 sensors corrected but still runs bad (how was it discovered that the O2 sensors were switched, it’s possible they were damaged and now need replacement)

You might need to do a hard rest of the DME by unplugging the battery overnight

-Yes Jb4 was in for several months and car ran great
-correct
-I went to autocature in NJ and they check the code and corrected the issue (the car ran fine with the jb4 off after this as prior the car ran like shit constantly)

I might add that it doesnt happen EVERY pull... id say 98% of the time

i am thinking it either

Bad o2 sensors from when they were switched (idk if they go bad)

or plugs and or coils.

Car has 45k on it and im sure were never changed (bought it used)

[Jeff@TopGearSolutions]

Probably spark plugs if they are original.

[WilliamS]

First you can reset all learned values by using Category 1 selection 7 will clear adaptations. Try that bcuase you might not be fueling properly due the air amounts. Are you 100% sure the 02's are in the right place. Turn off the Autoclear Check light codes. If you dont know if you have it on go to screen 1 and use option 4 and get out of the menu as normal when you use the track down button on your steering wheel.

Car idle do the 1/7 clear adaptations let it idle for a little bit. Go to map 4, which is factory boost but allows the JB4 to keep track of codes and such. Drive the car 10 miles, some boost some without. From there go to map 5 and drive again. If your still getting a stumble use the JB4 to figure out what codes. If it throws a code, use the JB4 to figure out what it did and why. If its a missfire use the cable to see what your long term and short term fuel trims are. As well note which cylinder the missfire was on.

Report back when your done.