2004 rxp engine running extremely rough and slow.

[Droop1120]

I have a 2004 RXP and it starts easy enough but when in idle the engine shakes really bad, and there is a rattling noise. Also, it wont accelerate faster than 7 mph. I was thinking maybe it had a dead cylinder, but i dont think it would be that weak if it did. any help is appreciated, thanks.

 

[mikewendricks]

I don't know much about working on these things but when mine would barley go I just changed the plugs and it was fine. Try that