cMarius

I just bought a mazda rx-8 and I lit for the engine lit on the board, I did a test with odb2 and I have the following codes: p2096 and p0139. I read on the internet about these codes and I'm still not clear how serious the problem is.

Loki

iTrader: (1)

P0139 indicates the rear oxygen sensor is broken. The other code is more likely a result of that sensor feeding wrong information. I'd suggest replacing the rear oxygen sensor.

Another possibility, although improbable, is you have a large exhaust leak before the O2 sensor that's causing both codes.