Random Misfire

[plex12345]

hi guys,

i need you help, 3 years ago i have swap my 318is engine to s52 with automatic transmission, the problem was i have been experiencing random misfire at above 6k rpm, at first it went away after i changed my spark plugs, but after i change my intake manifold to schricks the misfire didnt went away. i also tried using the recalled crankshaft sensor but it became worse since it misfired and hard started, btw my crankshaft sensor is located in the front after i used the adapter lead with the back sensor the car misfired even low rpm. i need help guys,

these are my mods:

AFE intake
Schrick intake manifold
ebay headers with full 2.5 inch stainless tube and dinan catback (cat deleted)

the parts i have changed for misfire issue:

6 ignition coils
6 spark plugs (NGK)
crankshaft sensor
camshaft sensor
02 sensors

[wtmeyer]

Check the rubber boot connecting the airfilter to the intake for leaks. I had a similar issue and found a slit in the rubber boot. Replaced this boot and problem went away.

[MIKYZZ4]

Remove rubber intake boot,
squeeze and carefully inspect all areas,
the cracks that were once hidden will appear.