Flashing back to stock running high-flow DP

seanroberts000 · 08-15-2021, 04:52 PM

I’ve had stage 2 BM3 with a CTS high-flow DP, combined with xHP Stage 3 Trans tune — loving it.

Went in for my NH state inspection, didn’t think to flash back to stock and got OBD not ready — failed.

The shop said flash back to stock for 100 miles and retest.

I can keep the DP on without worry using stock flash, right? Anything else I need to do in preparation to pass emissions test?

Thanks!!

Ajowhan · 08-18-2021, 07:56 AM

Yes, you can keep the DP on without worry using stock flash. Not familiar with NH emission policy though. In Cali, we would have to swap DP back to stock.

Also not familiar with CTS high-flow DP, would it throw a CEL with stock tunes? If it does, I would think it wouldnt pass. If it doesn't, then it would depends on NH emission policy and whether it allow aftermarket catted downpipe.

08-15-2021, 04:52 PM	#1
seanroberts000 Enlisted Member 15 Rep 48 Posts Drives: 2017 M240i xDrive coupe Join Date: Sep 2020 Location: New Hampshire iTrader: (0)	Flashing back to stock running high-flow DP I’ve had stage 2 BM3 with a CTS high-flow DP, combined with xHP Stage 3 Trans tune — loving it. Went in for my NH state inspection, didn’t think to flash back to stock and got OBD not ready — failed. The shop said flash back to stock for 100 miles and retest. I can keep the DP on without worry using stock flash, right? Anything else I need to do in preparation to pass emissions test? Thanks!! Last edited by seanroberts000; 08-15-2021 at 05:06 PM..
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08-18-2021, 07:56 AM	#2
Ajowhan Lieutenant 254 Rep 515 Posts Drives: m240i 'vert Join Date: Feb 2021 Location: CA iTrader: (1)	Yes, you can keep the DP on without worry using stock flash. Not familiar with NH emission policy though. In Cali, we would have to swap DP back to stock. Also not familiar with CTS high-flow DP, would it throw a CEL with stock tunes? If it does, I would think it wouldnt pass. If it doesn't, then it would depends on NH emission policy and whether it allow aftermarket catted downpipe.
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