tuned e36m3 P0101 code

[maxwelll]

Hey all. New to the e36 platform and hoping for some assistance in diagnosing an issue i've had with the car.

The car:
obd2 '99 m3
-rebuilt vanos
-vac motorsports springs and retainers
-cams
-evap delete
-secondary air delete
-rear o2 sensor delete
-s50 intake
-3.5" porsche maf
-3.5" intake with aem filter
-bw silicone hose kit
-24lb injectors
-new fuel filter
-oil separator delete with moroso catch can
-custom bpc dyno tune

What I am experiencing is an OCCASIONAL low idle dip/ stall while at temp (oil temp between 200-220), when idling down to a stop. The car only throws a P0101 code, and even when clearing on my (cheap shit) scanner, it immediately shows pending P0101 with ignition off. The car will run with no check engine light until the ignition is cycled again, and the light will re-appear on the dash.

This car was built... and built well... but before I took possession of it. What am I looking at here? Do we suspect MAF?

Before I dig deeper into the car, let me know your thoughts here. Appreciate it!

[AJLM34A]

Check to make sure that the black and brown wires for the MAF are connected. Just peel back the outer cover away from the connector, that is the easier place to connect the 2 wires.
Screenshot 2025-06-12 at 6.48.52 PM.png

[maxwelll]

I'll check this, thank you. I've currently got the MAF off after re-clocking it a few times, i'll check this now. I do remember reading up on this.

After checking this, and cleaning the MAF i'll see where the car stands. I'll also run the car for a bit with the MAF plug disconnected to see how the car does. After this it seems the next appropriate step is to snag another 3.5" Bosch Porsche MAF from bimmerworld.

Please keep the ideas coming. I am a seasoned enthusiast, but new to this platform entirely.

[BMWManiac]

I would always do a smoke test too

[Braymond141]

I'll check this, thank you. I've currently got the MAF off after re-clocking it a few times, i'll check this now. I do remember reading up on this.

After checking this, and cleaning the MAF i'll see where the car stands. I'll also run the car for a bit with the MAF plug disconnected to see how the car does. After this it seems the next appropriate step is to snag another 3.5" Bosch Porsche MAF from bimmerworld.

Please keep the ideas coming. I am a seasoned enthusiast, but new to this platform entirely.

Bremi “803” do not require bridging the grounds. Most sensors purchased in the past 5 years are Bremi.


Only real Bosch 803, and 809 require ground pins 1 and 4 to be bridged.

[maxwelll]

I found this to be true as well.

After some further research it does seem the ICV hose has degraded a bit. I will be pulling the ICV and cleaning it/replacing hose, and from there check for leaks.

I suspect it may be ICV or a hot idle vac leak/icv stick. The issue only presents itself when the car is hot (oil over 200deg) and only intermittently. The pending P0101 code only re-appears after cycling the ignition after a longer cruise, where the hot idle issues present themselves. My best guess is the DME is detecting a minor leak when hot and allowing that pending code to 're-stick'

I'll replace the ICV hose and clean ICV and report back with findings.

Off topic: What are people using to log? Should I snag a bimmergeeks cable for some basic logging via laptop?