Misfires
 

1999 SLK230 Kompressor.
I'm showing codes for misfires on 3rd and 4th cylinders. My MB mechanic can't pinpoint the exact problem and doesn't want to dollar me to death chasing it. His diagnostic equipment isn't compatible for this aged car. I've replaced the coil packs, plugs, and plug wires in an attempt to DIY what I can. No help there. The only time I have a problem is when I get into the Supercharger. Then it goes into limp mode. I shut it down, restart, and it's back to running normal, until I get into the Supercharger again. Then back to limp mode, shut it down, restart, rinse and repeat!!

Any suggestions???????