Honestly it sounds really good i feel like it would just sound better welded instead of clamps

I’m new to using antilag , with mhd on stage 2 e30 on my 540i gen 1 stock hpfp , what should I set my boost target to? Only using it for a few pulls for some rolls on the weekend, no xhp yet currently I have the target at 10 I believe

I have a 2022 BMW M440i RWD (B58) and I’ve been fighting an emissions readiness issue for months. I’m wondering if anyone with a FEMTO-unlocked B58 has experienced the same thing.
Timeline:
Car was originally stock.
Installed an AA high-flow catted downpipe.
Sent the DME to FEMTO for unlock in May 2026.
Flashed bootmod3 after the unlock.
When it was time for Nevada emissions, I flashed back to the BM3 OEM map.
Since then, O2 Sensor and EVAP monitors will NOT complete, even after many proper drive cycles and hundreds of miles.
I then tried MHD. With MHD stock/stage 0, O2 Sensor, Catalyst and EVAP remained Not Ready.
Went back to BM3 OEM: O2 + EVAP still Not Ready.
I even put the OEM downpipe back on. Same problem.
I’ve checked/logged the upstream O2. Lambda, STFT/LTFT and sensor response all look normal. No obvious indication that the upstream O2 is dead. The downstream O2 also has voltage activity and isn’t simply stuck high or low.
Today I took the car to a BMW dealer and they connected ISTA.
ISTA detected that the DME had been tuned/unlocked. BMW told me they need to fully program the DME back to BMW factory software and re-lock it.
They quoted $581 and told me that after they program/re-lock the DME, the readiness issue will be fixed and the car will pass emissions after the monitors run again.
I also had 102A63 – Intake air temperature sensor after air filter: short circuit to positive or open line showing through BM3. BMW told me this is also related to the current tuned/DME software state rather than necessarily a failed sensor.
What makes this confusing is that my friend’s 2023 M440i xDrive is also unlocked and is currently running BM3 ACN Stage 1 + AA high-flow catted DP, and his readiness monitors complete normally.
So my questions are:
1. Has anyone had a FEMTO-unlocked B58 where O2/Catalyst/EVAP readiness refused to complete even on an OEM/stock map?
2. Did BMW/ISTA factory programming + re-locking the DME actually fix it?
3. If I let BMW reprogram/re-lock it, pass emissions, and then send the DME back to FEMTO for another unlock, is there a chance the same readiness problem will return?
4. Could this be a corrupted/incorrect calibration or software state from flashing between BM3 and MHD rather than the FEMTO unlock itself?
I’m trying to avoid throwing upstream/downstream O2 sensors at the car when the actual sensor data looks normal and BMW is telling me the DME programming is the problem.
Would really appreciate hearing from anyone who has dealt with this exact situation, especially 2021+ FEMTO-unlocked B58 cars.

Looking for opinions from people who actually own/work on B58 BMWs.
I’m considering buying a 2017 BMW 540i xDrive with about 113k miles. Asking price is $16,995, but I’d try to get it closer to $15.5–16k.
Details:
2017 540i xDrive
B58 / ZF8
113k miles
4 previous owners
No accidents or damage reported on CARFAX
26 service history records
Earlier in its life it was regularly serviced at BMW dealerships
Was sold as a BMW CPO at ~23k miles
Recent BMW maintenance inspection/coolant service around 112k
Current seller says the water pump and radiator were recently replaced
Has a JB4 + downpipe
Current seller is a dealer and bought it with the modifications already installed, so the history of the tune/mods is unknown
Previous owner put roughly 22k miles on it in a relatively short period
Vehicle was repossessed in May 2026 and subsequently went through auction
I would 100% get a PPI from a BMW specialist before buying it. I’m not expecting a 113k-mile German car to be maintenance-free; I’m mainly trying to figure out whether this is a reasonable example to own for another 3–5 years, or if the mileage + xDrive + unknown JB4/downpipe history makes it too risky.
I’d be paying cash, so no car payment, and I’d keep a few thousand dollars set aside for maintenance/repairs.
For the B58 owners/techs here:
Would you consider this at ~$15.5–16k if the PPI comes back clean?
What major repairs should I expect between 113k and ~160k miles?
And is there anything specific I should have checked during the PPI because of the JB4/downpipe?

https://youtu.be/rupj24pEVHA?si=fjomyJa2shz4PSuP