O2 Faults

[mikefocke]

and didn't crimp them correctly and so are giving bogus signals to the ECU is my guess.

Bosch makes the ones Porsche buys and Bosch has multi-million dollar machines that do the crimp and then test. I've used them to replace both my pre-cat sensors.

[Paul_B]

When my CEL kept coming on for various 02 sensor faults the first thing I tried (based on what I'd read in these forums) was to thoroughly clean the MAF with electrical contact cleaner and Q-tips.

No problems since then and that was almost a year ago. Probably worth a try for a few dollars worth of cleaner, although you do need some tamper proof star (torx) bits to get at the sensor.