Cylinder 4 Misfire - New coils / plugs / fuel injector

[izaazk]

hello -

I am trying to figure this misfire out... bought the car 2 days ago and drove fine and we pushed it hard during test drive. Drove fine for 10 hours straight then when we downshifted, it triggered a misfire and Drive Train malfunction.

I replaced all 8 spark plugs and ignition coils with oem BOSCH and replaced 1 fuel injector on cylinder 4.

Cylinder 4 seems to constantly misfire as soon as the engine starts you can hear it. (Combustion misfire code)

Compression test is the only thing i havnt done yet... any ideas here or am i F**KED after just buying the car

[M5Rick]

Sorry to hear that, I'd do the compression test to get a fuller picture.

[Kamate]

You didn’t say if you coded the new injector. But if you didn’t, you have to code it. Other than that, do the compression test like Rick said.

[izaazk]

Compression test came out okay all 1-4 cylinders are 170-180 in compresssion

We did code the new injector

We are doing injector actuation test and turning off cylinders 1,3,4 all cause they engine to stumble but 2 doesn't do anything so I wonder if it's something