Hi Steve,

I was so hoping you already had this done, solved your situation 100% and cost $50!!! I'm going to stop by the Indy on Monday with a print-out of your post and talk with their MBz tech and see what he thinks.

Suignami (I think I mispelled his name) has been nudging me to look into the intake manifold. He had a similar problem, but his car was a 320 - not a 400/420. Also, the shop said they did the carb spray thing, but I don't know if they checked around the intake manifold.

I've thought about trying myself, but saw a very high potential for blowing my head off! And, since you said there wouldn't be a change in idle perse and that the reading the changes in the O2 sensor would be check, I can't do that at home. The perfect excuse to watch college football!

I'll keep you posted.