I have a 2011 mcs and it’s throwing a P045B code and the cold start is a little louder than normal but that’s the only real difference I can tell. I’ve replaced both the camshaft and crankshaft positioning sensors and the problem went away for about a month and now it’s back. Does anybody have any input on what this might be?

 

What about your VANOS solenoids? Also, how many miles on your timing chain?

 

haven’t checked the solenoids but I will be tomorrow. Timing chain has almost 85k on it. It’s the one that came on the car as far as I know. I also have a bigger intercooler, catless dp, Invidia exhaust, colder plugs and a stage 2 RPM tune. Idk if that would have anything to do with it

 

I’m curious, because the P045B code is the general OBD code for exhaust gas recirculating fault. That would make me think cam timing related on the N18 engine, but I don’t know for sure.

Since you’re running an aftermarket tune, might want to invest into a BMW/Mini scanner to check for DTCs, which are not picked up by the generic OBD scanners. I’m sure there are other codes in there to tell you what’s going on.