2005 Chrysler 300C, turns over but will not start.
 

It will start and run poorly if you give it about half throttle. The only code in the PCM is code P0300: multiple cylinder misfire. It has good spark, 60 psi fuel pressure and 160+ psi compression on all cylinders. I have put a smoke machine on it looking for a vacuum leak and did not find any.

I have also checked the exhaust back pressure and did not find a problem. When it does start the exhaust smells rich. Data stream readings are not showing any that are way off. Has anyone else seen a problem like this?

Thank you for any replies.