I have a 2000 Taurus with a V6. My check engine light is on and according to Advanced it is both O2 sensors. The front sensor was recently replaced due to damage. I know there is no garantee the new sensor is good but before I replace both sensors is there something else that would cause this? Some days the car runs fine, other days it surges and will die at idle. When going uphill or accelerating sometimes there is valve rattle like the timing is off but I see no way to adjust the timing.

 

Please post theEXACT code numbers and we can better assist you.

 

There are three codes coming up;

PO135 O2 sensor bank 1 sensor 1
PO155 O2 sensor bank 2 sensor 1
PO171 system too lean

 

The first 2 codes are for the heater circuit in the O2 sensors. I would look closely at the wiring to be sure there are no breaks, chafes or bad connections. The 171 could be caused by a vacuum leak, bad MAF, engine misfire, bad fuel, and a lot of other things. Since you stated you are experiencing noise on acceleratrion, I would look closely at the MAF. You need to have the baro read on iot and cross it to the correct altitude. Ford has a problem with them reading wrong. Good luck.