Hey just thought I would share some info I found. Recently got my 740 back on the road. All went well for awhile. I replaced a few vacum lines one day, and the car ran like crap. I was stuck. It was running real rich and sounded like it was missing. It wouldn't idle and did smooth out after it warmed up but was still rich. The car actually sounded like I dropped a cylinder. Coughing and sputtering, like a old one lung engine. I got a offer on the car and almost sold it. This was basically all the same problems I had before. But this time no codes or check engine light. I got on another sight looking for old dodge parts and got chatting with a fellow volvo fan. He asked have I checked the manifold air pressure sensor. I didn't even know I had one. Long story short, it has a plastic vacum line running from it. I must have broke it working on the other lines. Very easy fix since I had already bought lines to replace some questionable ones. If replacing the line is not the solution the part is only about 50 bucks at autozone. I may buy one for later, I've replaced every other sensor besides that one. But the car is purring like a kitten once again.

 

I love it when you think you have a huge problem, and then it turns out to be something as simple as that. It makes life so much easier.