I'm having problems with my 89 745 Turbo. What started out as a bit of a rought idle a few weeks ago has turned into situation where the car won't accelerate very well, and stumbles or bogs down when accleerating. I can feel a bit of vibrations when this bogging down occurs. When it reaches the desired speed, it seems to run smooth. It also still periodically idle rough, and when it does, it seems to shake like its running on three cyclinders.

could this be a symptom of a clogged cat?
or maybe a bad Air Mass meter?

I've just recently put in new fuel pump and radio supression relays.

I plan on taking the car to the shop next week, but was thinking about putting in a used Air Mass meter to see if that might cure the problem.

thanks for any advice.

-Bruce