[cheddarcheese1204]

So I was flooring the gas pedal on the highway and was going about 70mph then i heard clanking coming from the engine bay. Check engine light came on and drivetrain malfunction. The check engine light went away after about 3 seconds. The car had trouble revving and was going 30mph for about 2 miles on the highway then went to a complete stop. As soon as it was in a complete stop, the car started shaking and the exhaust sounded very off. The engine failed to rev and the check engine light popped up again for 3 seconds then the engine stalled. I start the engine again and everything worked perfectly fine. The drivetrain malfunction notification didnt pop up. Drove for 5 miles back home with no issues. I used the mhd adapter to see if there were any fault codes and these popped up. I have a 540i 36k miles with catless installed, mhd stage 2 and xhp stage 2. Any help would be much appreciated.

- DME active codes -
120408 - Charging pressure control: Switch-off as consequential reaction.
140001 - Combustion misfires, several cylinders: Fuel injection is switched off.
140004 - Combustion misfires, several cylinders: Exhaust gas damaging.
140010 - Combustion misfires, several cylinders: detected
140101 - Combustion misfires, cylinder 1: Fuel injection is switched off.
140110 - Combustion misfires, cylinder 1: detected
140201 - Combustion misfires, cylinder 2: Fuel injection is switched off.
140210 - Combustion misfires, cylinder 2: detected
140301 - Combustion misfires, cylinder 3: Fuel injection is switched off.
140304 - Combustion misfires, cylinder 3: Exhaust gas damaging.
140310 - Combustion misfires, cylinder 3: detected
140401 - Combustion misfires, cylinder 4: Fuel injection is switched off.
140410 - Combustion misfires, cylinder 4: detected
140601 - Combustion misfires, cylinder 6: Fuel injection is switched off.
140604 - Combustion misfires, cylinder 6: Exhaust gas damaging.
140610 - Combustion misfires, cylinder 6: detected

- DME shadow (inactive) codes -
11A030 - Low-pressure fuel system, electric fuel pump, adaptation: Adaptation value outside valid range.

[adhrp]

Not sure about this exactly, but sounds a bit like when my LPFP died. I wasn't in motion but upon start up the car shook vigorously, sounded like misfires, and it shut down. I do see a LPFP code there among your codes.

[Joe-BMW33]

I’m an not an expert but experienced with BMW’s. When you were stuck at 30 with no power or response on the gas pedal, that was limp mode. The car puts itself into it to protect itself.

The codes appear to be multiple misfires across all banks. If it were a plug or a coil, it would be just one or two entries for misfire. Looks like you had eight misfires which leads me to believe the engine was starved of fuel suddenly. The exhaust fume codes are concerning and most likely have to do with your catless downpipes.

You got a lot going on with tuning and downpipes. Does your tune require 93 octane or better? Could you have put some shit gas in that wasn’t high enough in octane? That would explain the knocks for sure. When you pounded it, the tune could be calling for some juice and there wasn’t enough in the mix.

If you blew a rod, there is no way it would have started up normal after a stop.

Unfortunately, when you do as much as you’ve done, you’re deviating so much from spec that as some point, you’re going to be chasing issues.

[cheddarcheese1204]

Yeah the tank had 93 octane with 30% ethanol in it haha. Do you think this caused permanent damage to the car?