This afternoon I picked up my newly Kleemanned '05 slk 350. Needless to say, car sounded amazing and had some extra oomph. However, a moment ago I started the car and the CEL was on. The car seems to idle roughly sometimes but not always. Also has a bit of clunking in the front when it idles roughly. Engine and tranny mounts are basically new. I will go check the code tomorrow, just curious if anyone has any insight because I'm a bit worried that this CEL is on.