RickBou

High all, I'm back with a continuing Escape problem. This is the same Escape from the thread "Multiple P035x error codes". Firestone gave a $500.00 refund because they didn't change the rear cat. They buy their parts from the same Carquest as I do, I called Carquest when this problem arose with the cats and they said they had the front 2 but could not locate the rear cat in any of thier nearby stores. Firestone said they didn't change the cat because it didn't need it. They now want to start changing O2 sensors. First, I was told that raw fuel came out of the tailpipe on startup. Second, 3 mechanics have told me that all 3 cats are probably damaged if raw fuel made it that far. Third, P0161 is the only code it is showing, I have read that it is for the last O2 sens after the last cat and it normally indicates the condition of the last cat. I am about to ruffle some feathers over this problem and want to be sure I am making a valid argument. I feel that it would make more sense to change the last cat BEFORE changing sensors considering what it has been subjected to. I just wanted your oppinion if I am on the right track.

Thank you again for all your help,

Rick

Bert

OBD-II Trouble Code: P0161 Oxygen O2 Sensor Circuit Low Voltage (Bank2, Sensor2)

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Bert

tomw

I thought 'bank 2 sensor 2' would be the lower sensor on the front exhaust, after the catalytic converter. Bank 2 sensor 1 would be the upper sensor. Bank 1 is the side closest to the firewall.
If you follow Berts link, it gives a decent explanation of the indicated problem. This sensor is used to check converter efficiency, and should be low problem.
tom