killerwatts

Last week I replaced all my oxygen sensors(walker post cat and SNG pre cat. I originally had a code for no activity detected on B1 S2 and decided since the mileage and the lack of maintenance records from previous owner to replace all. I had no other codes before then. Now the new pre cat sensors are giving me the code P1196 and P1197 which says electrical malfunction for both pre cats. They seem to be within voltage spec but when I monitor the working resistance I see 9.82 Ohms (which is what triggers the code) when it should be 9.2 ohms or less. It will not CEL until it has done it 2 drive cycles. Should I suspect the new sensors? I did pull my ECU and removed some corrosion but still no change. I still see a huge increase in milage performance as is but that CEL drives me crazy whenever it pops on. 1998 Audi A8 Quattro 4.2L 137,000 miles. I have done a lot of work since I got this car and am now down to just final pieces to complete the puzzle.

Always Overcharged

the sensors are suspect

PaulW

Did you put Bosch sensor in?

killerwatts

Walker post cat and SNG pre cat. The Walkers seem to be working fine and the initial CEL was from a post cat sensor. There were no prior pre cat issues before new pre cats were installed.