Cel p0173

[AstronautTurtle]

Have had a CEL for a week or 2, just checked it and it read p0173. It runs fine except for the occasional misfire. Any thoughts?

[Daox]

Interesting issue. I looked it up and found:

https://www.obd-codes.com/p0173

Potential causes include a vacuum leak, unmetered air leaks Fuel saturated engine oil Leak in turbo air charge hoses (if equipped) Possibly bad O2 sensor (If Mercedes, may require adaptation with M-Benz compatible scan tool.) Oil contamination in MAF connector or O2 sensor connectors. Also check ignition coils, cam and crank sensors, and oil sensor for leakage contributing to oil intrusion in wiring harness. Defective MAF (Mass Air Flow) sensor (especially on Mercedez-Benz and other European autos.