My 940 T (93), which I am using at approx 12 psi, was pinging under load. No reason that I could find as I have two other family turbos at the same pressure and no ping. It had to be lean, and at 135K the O2 sensor had not been changed according to the records. Put in a new universal Bosch 13913 O 2 sensor, and no more pinging.

Apparently the old one was dying lean. The vents on the sensor were starting to plug. BTW, this is about the 5th universal Bosch replacement I have used on both NA and turbo, and they perform flawlessly. Only about $40. too!!

dick

Dick, how did you wire it in? Crimp tube splice or solder? Where did you splice it: at the sensor or up toward the connector?

Given the importance of the O2 sensor to engine management, I try to change at 100k whether it needs it or not.

I soldered the wires, which was quite a problem. The wires are coated with a silver substance, but seem to be copper under. It takes a lot of heat, but eventually I won out. Don would have been proud. The generic Bosch comes with a neat plug, but don't know where to find an opposite end. I cut the original cable quite long and the replacement fairly long. Used a top grade 3M tape for the final sealant.

Considered using a crimp method, but was not too sure of a good connection.

dick