The owner of this Beemer has owned it a couple of years and – like a few others we’ve known – wasn’t overly impressed with it, having had a few issues.
He wanted it to sound a bit better so had fitted a can; power increase wasn’t really on the agenda, just a general sort out. We started by switching off the lambda and Secondary Air injection System (SAI) and then fitted the PC III which is a big job on this particular model.
After setup it was better, but still had areas that could be better. There is a lot going on between the ignition and fuelling maps in this engine that aren’t immediately obvious – the PC III gets around some of these, but doesn’t cure anything, it just masks the problems.