First of all, thanks to the hosts for this great website and forum. It is a great help!

I have a '98 ML320 with 127,000 mi and an intermitent check engine light. I went to local independant shop and got stored trouble codes P0300, P0303, P0305, which indicate misfire on cylinders 3 and 5. His suggestion was to replace the ignition coils on 3 and 5, and new plug wires and new plugs. I have done so and it did not fix the problem.

Car runs fine except: when fully warmed up and left to sit at idle for extended period, such as at a long stoplight, it will begin to missfire. I can turn off the engine for a minute and start up again and it will be fine, untill the next long stoplight.

What else could be causing such an intermitent problem? Engine position sensor? If anyone has seen similar problem or any ideas it would be greatly appreciated.