dtar3

Getting code P0154 after a sport cat install. All sensors are new except for the upstream bank 2 sensor... could this be the culprit? Which sensor is Sensor 1 and which is Sensor 2? Thanks!

Petza914

100 cell or 200 cell cats and what brand? All 100 cell cats will throw a cat efficiency code unless tuned out. Cheap 200.cell cats like Top gear will also throw codes but done have gotten away with those using an O2 sensor spacer. High quality 200 cell cats like Soul Performance and Fabspeed that use HJS catalytic converters won't throw codes.

dtar3

200 cell, I'm not getting a CEL from too lean or too rich. The code is that the sensor is not reading at all. I've replaced all Bank 1 sensors and the downstream on Bank 2. I have a "Bank 2 Sensor 1 no output" code. I guess my question is more simply asked as "which sensor is Sensor 1?"

Petza914

I would replace that one. Hopefully whoever installed the cats took thebO2 sensors loose from the sensor blocks at the back and didn't just twist up the wires to remove them from the old one and install in the new one as that could certainly damage them.

991Targa4S

Bank 1 is usually Rh.
Sensor 1 is always upstream & sensor 2 is downstream.

Petza914

On a US 911, bank 1 is the Driver's side and bank 2 is the passenger side. If the cats you bought are crossover cats like the OEM that can change how you look at the sensors, but the engine banks don't change.

dtar3

Exactly what I was looking for and wanted to hear, thank you! I was petrified it was a wiring issue. Fingers crossed a new upstream sensor fixes this.