After driving around for about 20 miles or so came to a stop when I went to take off pushed on the gas peddle and real slow to get any rpm push more on the peddle and just like there way a delay on the rpm ? pulled over turned the car off and restarted it and ran normal its done this twice now no lights on the dash ? Has any one had this happen ?

 

More information would be helpful to find a solution to your problem. Such as; year, NA or SRT-6, manual or automatic transmission.
I would suggest that you also use a scanner or have an auto-parts store scan it for you to see what codes come up.
My guess would be the throttle pedal sensor.
Here is a thread about it. If you read the whole thread, one of the members describes your problem.

Throttle pedal position sensor

 

Sorry its a 05 roadster auto with 82,000 miles and went out yesterday with it and my check engine lite came on this time stopped at auto zone code was p0121 so is it the pedal sensor or the throttle position sensor I got to get a code reader just don't know witch one to get yet.

 

I read a post and apparently the correct Mercedes-Benz part number is: 170-300-01-04.

The cheapest one I found is here: (You may have to grab a VIN from an SLK 320 for sale online to check out).

https://www.mbdirectparts.com/oem-pa...dal-1703000104

 

I put a used accelerator gas pedal from Playground parts and a 74mm throttle body from needswing . Took it out yesterday went over 130 miles so fare running real good. I should have replaced one at a time to see witch one was bad

 

Thanks for the update. I'm glad that it's running good!