Need some help in figuring this out as I did not find anything helpful after searching the forums for the problem. I have had the check engine light on for about 1000 miles but the engine runs fine with mileage down a little(2 mpg). When I used my new ODB-II tool (Autotap software running on my laptop) I received the following DTCs.
P0133 Oxygen sensor circuit slow response bank 1 sensor 1
P0420 Cat system low efficiency bank 1
P1131 Lack of HO2S11 Switches sensor indicates lean
P0133 Oxygen sensor circuit slow response bank 1 sensor 1
P0420 Cat system low efficiency bank 1
P1131 Lack of HO2S11 Switches sensor indicates lean
P1151 Lack of HO2S21 switches sensor indicates lean
Notice the first 3 DTCs are listed twice and I have never heard of that before. Anyone seen this?
So, is the combination of the P0133 and P1131 indicative of a failed bank 1 upstream O2 sensor?
I am guessing the P0420 is related to the same problem as the O2 sensors, the cat requires the O2 sensors to be working for it work work correctly.
Any help is appreciated.
Eric
1998 Contour SVT totally stock, 60k miles
