My clk 430 has had its problems over the years, but I still love it. After 2 new front bumpers due to me and parking stops. Last summer I had the check engine light which a local dealer here said it could be alot of things since it was fuel trim problems on both banks. They said they would need it for a few days and then may have to replace a bunch of parts til it was fixed. I was like umm I will buy my own computer and do it. Well it ended up being the Air Mass Meter which I learned from posts. Replaced it no more light I never had a performance issue. But ever since that and a new O2 sensor when driving in the heat this summer (80 and up) when I hit the gas off the line it starts to go then the engine slows back and it just feels like it is sluggish and the transmission shift pourly.

So I thought it just needed a tune up which it did. So I replaced the spark plugs, wires, and fuel filter and still the same thing. When it is cool out it runs like a champ no signs but once it gets hot out it starts. Any suggestions as to what it might be????

Thanks,

Phillip