E70 X5 4.8 Misfire Cylinder 4 2E27 after replacing spark plug and ignition coil

[anthonyt]

Hey guys hope you can try and help me out here. Since 8 months back I started to notice the rpm would dip very slightly and come back on when the car is idle at the traffic lights. It used to be smooth. Upon scanning, there were no error misfiring codes present and no check engine light displayed. As the car is now 13 years old I decided to replace all the ignition coils and spark plugs brand's Bosch thinking that I may eliminate the problem. Also replaced the O2 sensors.

After the new parts has been installed, the car started throwing codes DME 2E27 Ignition Coil Cylinder 4 and 2B65 Cam Shaft Sensor 2 Exhaust. I swapped the coil and spark plug to Cylinder 2 but code remained on Cylinder 4. Re-installed the old ignition coil but the results were the same. This got me really baffled. Did a continuity test on the ignition coil 2 and 4 wiring results showed wires are not broken.

Next I did a scan and noticed that the knock signal for cylinder 5 is reading 0.15v which is lower than the other cylinders. Rough Running Value on cylinder 4 & 5 showing 8.22 and 8.83 1/s2 respectively while the others showing negative values.

Do I need to perform a reset on engine adaptation after the change out or something similar ?

Thanks in advance.

[andrewwynn]

When I had similar cylinder errors the problem ended up being dirty injectors.

If you got an error related to cam sensor replace both from that type (exhaust/Intake). It's a miracle when you get a CPS related error you usually have to guess based on symptoms. Use only OEM sensors or you will get random errors without any mention of the CPS.