CEL P0134 & P0139

[f-castrillo]

So I installed my CNT DP (w/ high-flow cat) yesterday, and I did some WOT pulls right after the install with no issue. AP's Live Datalog showed me hitting 1.9-2.1 calc load throughout most of the RPM range, MAF g/s peaked at ~260, and KR didn't exceed 1.0 during the pulls. No CELs.

Fast forward one hour, and the CEL comes on during a light 5 minute drive to Jack in the Box. I use the AP to pull the code, and I come up with P0134 and P0139.

Now as I understand it, P0134 indicates that there is no reading coming from the primary O2 sensor. To further confirm that there is a problem, the AP's Actual AFR parameter reads a constant 14.7, no more, no less, regardless of whether I'm at low throttle, part-throttle, or WOT.

P0139 seems to indicate that the secondary O2 isn't receiving enough exhaust flow. I have CNT's CEL "fix" installed, which is basically an L-shaped defouler installed to the secondary O2 sensor location. I may try removing it to see what happens, but I was under the impression that having the secondary O2 closer to the exhaust stream would cause the ECU to throw the "inefficient cat" code.

I want to rule out a bad sensor, because I really don't want to buy a new set, since they cost lots of $$$. I didn't strip either sensors removing them from the stock DP. Are the sensors easily damaged? Is there a way to clean them? Other than that, the only thing I can think of doing is checking to make sure the wire harness connections are plugged in, and uninstalling the "fix" (defouler) from the second O2 sensor and just plugging the secondary O2 straight into the bung.

Thanks in advance guys.