My CL500 (MY2000) had a flat battery while camped at Silverstone for the MotoGP last weekend (like an idiot I sat for ages watching TV for the first time - it doesn't work where I live), and as the AA weren't likely to want to drive against all the traffic and come and find me, I had no option but get a jump start. Luckily I didn't blow the SAM, and all seemed Ok. However, the next morning the dreaded check engine light was on! I don't think the flat battery/ jump start caused my problem, but I mention it in case its relevant - it seems a heck of a coincidence to me. I drove home with no problems, but with the light on, and it has since gone out. For peace of mind, I booked the car in for a diagnostic check with a specialist. The restart from a flat battery caused all sorts of codes, apparently, but the one that didnt go away was 'P2003 malfunction of secondary air injection (P0410)' Stored - and P2086-002 (left bank Enleanment below permissible limit) Current & stored, also P2017-002 (same, right bank). To fix this, the quote is £720 to replace the pump and relay. I can't do it myself as STAR needs resetting, apparently. 2 Questions: 1) As the EML has gone out now, do I need to throw £720 at the car to fix a problem which has gone away, or will it come back and bite me if I don't? From what I understand reading the forum, the only effect is on emissions - maybe it will become an issue at MOT time? 2) I have a warranty with Autoprotect ( bought from the dealer when bought the car) which I have really assumed (after some internet research) was a waste of money, anyone ever get paid out for this sort of fault? Again I dont want to have it done unnecessarily, then get left holding the bill, but if they would pay to fix it, I'll have it done so I don't worry about it coming back to haunt me in the future.