Here goes,

Bought a 1996 960 from a dealer in Texas. Drove it home to Calif, and ONCE on the way home it stumbled (had a rough idle). Once home we took it to the dealer to have the 90K and 100K service done. Soon after the dealer service, it started to stumble more often. It would run great for days then it would stumble at once traffic light, and be fine by the next one. Soon, it would do it every day. One minute it would run great, the next the engine would be shaking. So, the nearest Dealer is 60 miles away. The check engine light starts coming on and flashing. So, I take it to a local Volvo specialist. The codes show misfires on three cylinders and he shows me that the bottom of all coils are cracked and the wiring around the coil connectors is green and falling apart. So, I replace all six coils (thank you AllOEMVolvo.com), and he splices in a new connector to replace the worst one. By now, the engine has been shaking so much that the cat converter goes out. So, $600.00 buys me a rebuilt one. But, the misfires continue. The dealer recommends I put in a whole new engine harness. So, I go to the junk yard and buy a new section of harness (the section where all the coil connectors are) and splice it in. The car is back to working great one day and barely running the next. Take it to the dealer and he messes with the injectors and the coils. He does not know what is doing this. The only codes we are getting from the ECU is missfire codes. Dealer gives up and says its the harness. So, I finally give up and spend $1150, and get a whole new engine wiring harness put in. That was three days ago, car runs great. Lucky me. Now the passenger seat wont work, oy.