My car, a 1990 Mondial T, was throwing CELs like beads at the Mardis Gras. Now it is is perfect. Here's what I did: Replaced one O2 sensor. Replaced the phase sensor. Replaced the "electrovalve" that controls the compensation valve. Replaced the fuel pump and motronic (?) relays with new Tyco relays. Pulled all the shims under the rev sensors to reduce the gap to nearly the minimum. Liberally, and by the directions, treated all of my electrical connections with DeOxit5 which is better than Stabilant. Treated my MAFs with CRC MAF cleaner spray. Warmed the car up to full operating temp, disconnected the battery for about 5 minutes, and did a 10 minute idle, followed by a 120 mile drive. Lights were going on and off the whole way on the drive, but the next day they were off and have stayed off, (except of course when I start the car.) Of course I didn't do all of that in one sitting from start to finish: the whole process took me about 8 months, and a lot of puzzling over the codes and reading the service manual.
You verify the ohm setting on the MAF? Many people tweak that to "correct" unknowingly bad O2 sensors.... No Doubt has the reading & how to check it on his page- easy 2 minute process to verify.... Chris
