My 1998 SLK 230 170 has a misfire when I accellerate.
When driven sedately all seems well and will accelerate slowly to 70- 80mph (as far as I have taken it).
If I accelerate hard the engine will rev to between 3000 to 3500 rpm then go into misfire and not rev any further. After I have done this the engine runs really rough at idle and has no power. If I then switch off ignition leave a couple of minutes and restart it seems ok again.
Diagnostic meter says: P0300 random misfire
P0301 cyl 1 misfire
P30170 fuel trim(bank 1)
P0304 cyl 4 misfire
P0341 camshaft position sensor bank 1 or
single sensor
I have renewed HT leads, spark plugs, plug caps, and coils, but do not want to start replacing lots of parts if they are not needed.
Can anyone advise please.

 

Did you replace the Plug wires..I was getting the same codes and I replaced the Plug wires, coils and plugs and that cleared it up. Hope this helps.

 

I had the same exact thing. It ended up being the honey comb going bad in the catalytic converter. I would tap the converter first to see if something is loose inside.