135i n55 dct misfires cyl 2,3,4,5,6 after VCG and spark plug replacement !!

[Ruviol]

Hi everyone,
I need your help figuring out my multiple misfire codes on my N55.
The car was purchased with 55k miles. I upgraded Air Intake Filter, downpipe, and intercooler with stage 2+ MHD at 60k miles.
I have never has any codes or issues or any hiccups whatsoever, and the car now has 127k miles. the car run like a champ always.
I have had minor oil leakage through the Valve Cover Gasket which has gotten worse lately, so I decided to replaced the gasket and bought new BOSCH zr5tpp33 spark plugs since I was there already.
I decided to clean the dirty valve cover with degreaser and water.
I cracked the breather hose (known to brittle easily), but I fixed with marine heatshrink tube.
The new spark plugs were properly torqued to 17 ft/lb.
The Valve cover bolts were torqued to 6 ft/lbs.
I covered the Injector connectors so no debris falls inside.
I reused the OEM coil packs.
After reassembling everything back together I took the car for a test drive.
The idle was perfect, no fluctuations. The car behaved extremely normal until I hit the accelerator and it started to jerk and hesitate, and I got CEL codes :
2EE0 COMBUSTION MISFIRES, SEVERAL CYLINDERS
2EE7 COMBUSTION MISFIRE, CYLINDER 2: FUEL INJECTION DEACTIVATION
2EEA COMBUSTION MISFIRE, CYLINDER 3: FUEL INJECTION DEACTIVATION
2EED COMBUSTION MISFIRE, CYLINDER 4: FUEL INJECTION DEACTIVATION
2EF1 COMBUSTION MISFIRE, CYLINDER 5: FUEL INJECTION DEACTIVATION
2EF4 COMBUSTION MISFIRE, CYLINDER 6: FUEL INJECTION DEACTIVATION
2EFE COMBUSTION MISFIRES, SEVERAL CYLINDERS : DAMAGING TO CATALITIC CONVERTER
2F00 COMBUSTION MISFIRE CYLINDER 2: DAMAGING TO CATALITIC CONVERTER
2F01 COMBUSTION MISFIRE CYLINDER 3: DAMAGING TO CATALITIC CONVERTER
2F02 COMBUSTION MISFIRE CYLINDER 4: DAMAGING TO CATALITIC CONVERTER
2F03 COMBUSTION MISFIRE CYLINDER 5: DAMAGING TO CATALITIC CONVERTER
2F04 COMBUSTION MISFIRE CYLINDER 6: DAMAGING TO CATALITIC CONVERTER.

I double checked all hoses and connectors, they looked fine.
I cleared the coded with MHD and took it for a test drive and it was still the same, idle perfect low acceleration fine, but crazy misfiring under medium and heavy load.
I decided to install the original BMW BOSCH spark plugs back and the car still does the same thing, same codes same misfiring .

Is there anything in the crank case valve inside the Valve Cover that may have been damaged or cracked?

Any connector I may have damaged to cause this crazy misfiring on all cylinders but cylinder 1.

New spark plugs killed my coil packs?
I am lost
A vacuum leak maybe that I caused?
Everything in the car was working fine before the Valve Cover and Spark plug replacement.

Again this happens only under load or boost.



I appreciate the help .

[Snakevenom]

I just had the same thing happen.

[bimmerchic]

Same plus more issues... 👀

[Bordi35i]

Hello, check your lambda sensor connection and the cable. I've had a similar issue with my n54 last week only in one bank. The lambda sensor cable was sticking on the block and melted.

If you can log, check your AFR while driving. If it stays at the same value, you have a lambda issue.

Good luck!

[TWO STEP TEX]

I had similar issues when my valve cover was leaking. Since you did replace the gasket I'm inclined to believe that's where your issue lies. I would get a smoke test to verify before throwing money at it.