[daniel06]

Hey guys, I have an e90 318i (N46 engine) which I recently did a compression test on.

When removing the sparkplugs, I noticed a lot of oil on the sparkplug threads of #2 and #3. This makes me believe that I have a VCG leak so I will most definitely address this. However, after cleaning & putting everything back together and going for a spin, I get the check engine light with 2C9C & 2CA8 as stored fault codes.

INPA
2C9C: DME: Oxygen-sensor heater before cat. 1
2CA8: DME: Oxygen-sensor heater behind cat. 1

OBD Equivalent
P0037: HO2S Heater Control Circuit Low Bank 1 Sensor 2
P0030: HO2S Heater Control Circuit Bank 1 Sensor 1

These fault codes were not existing before I did the compression test. I checked the fuses and everything seems fine.

I'm thinking that maybe some oil leaked down in to the cylinders when I removed the oily spark plugs and maybe that caused the O2 sensors to trip, however I'm not quite sure..

Any thoughts on this?

[CLAUDE PREMJEETH]

Hello did the misfire go away because oxygen sensors can cause misfire and remove clean and clear fault and see if any fault coded