MAF relocation causing misfire and lean mixtrure?

Hello everyone.

VQ37, stock ecu tuned with ecutek

I had 3-inch intakes installed, which didn't perfectly fit my car (JDM vs USDM engine bay wiring, etc)

I was aware of the issue; however, I didn't think it was that big of a problem, so I went for a tune with the intakes that didnt fit well (as a place holder) ... presented no leaks or anything. Now, I've changed to a set of intakes that is made for my specific JDM model. The car is running ok, it struggles on idle and starts to stall out when I have the AC on. The only visible difference I can see from the two intakes are the total length of the piping and the MAF position with the new intakes having the MAF closer to the throttle body than the old set.

I'm not sure what is causing the issue, and regarding that, how should I be tweaking the maf curve? I can notice a torque dip around the 3-4k rpm range, but apart from that, it runs fair. Misfires sometimes, and on a cold start, it jumps to 2.6k rpm.

I would start by logging AFR (desired and actual) as well as STFT and LTFT. Combine all these things together to get an idea of what's going on at a base level.

I'm going through a similar process right now, but mostly higher RPM and higher load situations.

Once you have that baseline of data to work off of, you can adjust the MAF readings from there. I'm not familiar with ECUTek, but the Bosch ECU I'm working on (2013 VW GTI - MED17.1) with HP Tuners has a MAF Base Modifier table I'm using (as opposed to "airflow vs period", which I'm still working on figuring out) to make adjustments with some targeted logging data using total fuel trims (STFT + LTFT).

Hope that helps a little.