2001 Taurus SES P0136 O2 sensors
Using the OBD II, it read P0136. I changed all 4 sensors with bosch brand sensors. The check engine light stayed off for several days before coming back with the same code. I've been reading that it could be the wiring connected to the O2 senors. Also, that it could be the MAF sensor or a vacuum leak. Any hints, tips, or advice would be greatly appreciated!!!