[nscott32]

I bought this 318i from 2009 recently, 75k miles, and it's got these codes:

1. 2A99: Crankshaft - Exhaust Camshaft, Reference

1. 30DC- Nitroxgen-Oxide Sensor, Heating

This is my first car so I am very new to DIY with cars, but keen on learning.

Apparently 2A99 could be coming just from a dirty solenoid valve so I am going to try cleaning it this evening and see if the problem persists.

Does anyone have seen similar issues and solved them?

[nscott32]

So I cleaned the 2 solenoid valves and the problem persisted...
I have seen a few posts where people solved it by changing the sensor(s), I am tempted to buy one but isn't there a way to properly test them before spending the money?

[Suvorovo]

swap the two solenoids and check if the code moves to the other one. replace as needed.

Not sure if 318i has rareish cam ledge bearing issues like other n52 models.