EvilRob

I have had ETS V2 normal cat back exhaust with high flow cat (with 02 sensor bung) for about 3 months now, using Cobb Stage 2 tune.

Now the car runs perfect, keeps boost where it should be, detects no knock, and sounds great. I have one problem, that damn "Check Engine Light" keeps coming back. I used the software cobb provides unchecked the two boxes and clear the codes. The code will get cleared for about 20 miles after that it keeps coming back.

Currently I just have my wideband gauge 02 sensor in the high flow cat didn’t touch the down pipe at all (so if there is a stock 02 sensor in it I didn’t touch it)

No matter what I try the light keeps coming back, I tired plugging the stock o2 sensor back into the plug under the passenger seat and zip tying it under the seat, the light came back.

So I’m running out of ideas how to get that light to go away. My last attempt is to splice the stock 02 port (the one under passenger seat) with the wideband gauge that goes into the sensor in the high flow cat.

The P0140 code reads "02 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)"
First I thought that maybe because I didn’t have my stock 02 plugged into the port (one under passenger seat) that if I plugged it back in all would be fixed but that didn’t work. So if the splicing isn’t going to work would getting another bung welded into the high flow cat and running the stock 02 sensor to it fix the light?

If there is any other way that might fix my issue please do share. Cobb hasn’t been much help except for having me try using the software they provide for the tuner, that unfortunately does not remove the p0140 code permanently

Here is my little diagram