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      07-31-2016, 03:07 PM   #1
New Member

Drives: 2015 BMW m4
Join Date: May 2016
Location: Chicago

iTrader: (0)

Emissions test with JB4

I bought an M4 that has the JB4 S55 system on it and wonder if there is anything I need to do when I take it for emissions testing (in Illinois).

The seller told me to…

"Change to map 0 and then unplug OBD connection. This will bypass the JB4 and go back to factory tuning. Plug it back in when done and return to map 2."

Just want to be sure this correct and that it won’t un-do anything.

It also has this exhaust…

he mentioned that…

"I’m not sure how the downpipes will effect the test. You could reinstall the factory ones temporarily. If you do, you will have to run map 1 while the factory downpipes are on. Map 2 requires the aftermarket downpipes."

Naturally, I am hopeful that I won’t have to do that and am wondering if anyone has a few minutes to clear this up for me and let me know your views. This is all foreign to me.