Diagnostic Code P0340 - 2.2 M54

[wonderloaf]

Been having a few starting and idling problems with my M54 2.2 just recently: bad starting, lumpy idle, cutting out, flat acceleration. Put it into my local garage who diagnosed Vanos seal problems which were replaced accordingly, the old seals had started breaking up and some generally amalgamating into one part, not surprising really as my Z3 is now 15 years old with 92k miles on the clock and I understand this is a common problem.
Been driving the car for the last couple of days and thought all my problems were fixed (thought I'd got my old car back, she was going like stink!) when tonight the problems re-appeared. Put my little code reader on the car and got this code:

P0340 Camshaft position Sensor A Circuit Bank 1 or Single Sensor

Looking around the 'net this seems to be a very common problem, the only confusing bit is which sensor is being referred to as mine has both inlet and exhaust sensors. That said I've decided to replace both the sensors to be on the safe side, looking at realoem the part numbers are:

12147518628
12147539165

I don't really want to go aftermarket so want to buy OE or OEM parts, can you guys point me in the direction of the best places to buy these? I'll be contacting my local BMW dealer but just wanted to check if there any other places that might be more economical.

Cheers, Wonderloaf.

[Del]

Many have tried aftermarket camshaft sensors (me included for other cars) and they have been rubbish. It seems to be one area where OE is definitely best. I tried two in succession from GSF (VTECH brand) for a non-BMW family car and both worked very poorly, I managed to return them (can be a problem with sensors once used) and an OE worked perfectly.

[wonderloaf]

Many have tried aftermarket camshaft sensors (me included for other cars) and they have been rubbish. It seems to be one area where OE is definitely best. I tried two in succession from GSF (VTECH brand) for a non-BMW family car and both worked very poorly, I managed to return them (can be a problem with sensors once used) and an OE worked perfectly.

Thanks for that Del, that's definitely made my mind up to buy OE.
I was looking at GSF and ECP last night and their prices seemed pretty good, having just spent north of £500 on the Vanos seals I was tempted to economise a bit but don't think I'll risk it.

[wonderloaf]

Many have tried aftermarket camshaft sensors (me included for other cars) and they have been rubbish. It seems to be one area where OE is definitely best. I tried two in succession from GSF (VTECH brand) for a non-BMW family car and both worked very poorly, I managed to return them (can be a problem with sensors once used) and an OE worked perfectly.

Thanks for that Del, that's definitely made my mind up to buy OE.
I was looking at GSF and ECP last night and their prices seemed pretty good, having just spent north of £500 on the Vanos seals I was tempted to economise a bit but don't think I'll risk it.