I got a code P0135

[RocketFast321]

P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

Now which O2 Sensor is this on the 3100?

[TorquePower]

I'm just going to take a guess, which I'm sure you came up with the same logic as me.

I think it's the Upstream O2 Sensor in the exhaust manifold. Only because it says bank 1 sensor 1, and the second O2 sensor, only to my knowledge, just watches the cat.

So I'm not sure, just guessing on logic...

[RocketFast321]

no problems right now the light went off. ohh well

[TorquePower]

My car is doing the same. Just yesterday the light hasn't come on AT ALL....but a couple hours ago before I came home, I went to start my car and it was missing..., so I pushed the accelerator a little and it stopped once the RPM's came back down. :)