Three weeks ago I had the PNP switch replaced on my 850 wagon (105K miles). Tonight while driving at around 30 mph the transmission began to act up. It " clunked in to a lower gear without my stepping on the accelerator. It made some mild but discomforting lurching motion, and while in gear seemed to speed up and slow down erratically. I only drove it about 5 miles in all, but now I am totally paranoid about having to replace the transmission.

Please help with any advice / ideas as to the problem and the fix. I would like to keep this car but after replacing the PNP the o2 sensor the computer ($1000 - my wife spilled coffee on it) I am beginning to think it is becoming a money pit. Please help.