Just joined this site so I'm finding my way a bit..... I have a 2001 A208 auto CLK320. Car is fine until I floor the pedal..... Years ago it would drop two gears and of you'd fly. These days it will drop one gear and accelerate.... Then say when you'ce slowed down and stopped at a roundabout, you apply power and there's barely anything there and feels like you are pullinfg away in 5th gear. It does pick up speed though alnbeit perilously slowly and joining roundabouts becomes very difficult as others think yiu are deliberately messing around. Thing to do is pull over, switch off engine and romove keys, then after a minute restart car and it's drivable once again..... If I'm just casually driving and just accelerating in a more usual fashion and not flooring the pedal, you don't get the problem.... Tick-over is fine and no hunting or misfire.... I'm thinking MAF sensor. If I disconnect the MAF and then floor it, if the problem clears, can we then safely determine it's the MAF at fault or not necessarily? I intend to clean it with carb cleaner, is that ok? I would like to buy a code reader... It uses the old round type connector in the engine bay.... Any recommendations would be great.

Forgot to add....In the early days when this fault came about, there was no CEL.... Now it does light when the fault occurs.

 

Without a scan tool, you are looking for a thumbtack in the dark. Imagine trying to find a thumbtack at a football stadium in the dark with no lighting.

I'd suggest a decent scan tool, one that can read ALL systems. You could have a fault with the stability system which is preventing engine full power. Start with a scan tool.