Hello. I had the p2a00 code, so I changed the o2 sensor with a Bosch one. I changed the sensor before the cat, on the left side (if facing the suv....US passenger side). The code came back in later. Any ideas what to check next?
P2A00 means bank 1 sensor 1 is bad. Depending on your engine, you have to determine which side is cylinder 1 located. For Range Rover HSE 2002-2005, it is on the passenger side when you are sitting on the driver seat. Go under and change the O2 sensor (upstream, or the short one) before the catalytic converter. It is the first one close to the engine. I just changed mine and drove a few miles to complete the drive circle, and the code is gone. For clarity, it is under the passenger door next to the front wheel.
Check any wiring?
Make sure the wiring was getting correct voltage?
Check for any exhaust leaks?
Can you use something that is a little more specific, thats just a generic code from a cheap reader me thinks.....