Hey, my car is throwing 2 codes:

P0137 O2S Circuit, Bank1 - Sensor 2 low voltage

P0420 Catalyst System, Bank1, Efficiancy Below

Anyone ever have this? Are my o2's bad?

 

well, i am the king of the SES light mine has been on for 2 years strait for misc things.

Now to your problem. Yeah the bank 1 sensor 2 is the o2 sensor after the cat on the drivers side. The P0420 means your cat has either **** the bed or due to the bad o2 it can cause this code to be thrown since the o2 after the cat measures if the cat is working or not and if the sensor is bad then that can tie into your problem.

 

Sounds about right to me!

 

i cleared the codes, put on about 150 miles...ses is still off. car runs great...no lack of power, or throttle response. is it possible that there was just a surge in power, or a rock that could cause a trip?

 

More likely a short. If your o2's arent connected up properly or if moisture gets in there then it will toss all sorts of low voltage high voltage codes. Which can mean a number of things. A bad rear o2 wont mess with throttle responce at all. Just recheck the connections make sure everything is down tight and you should be good. If you get the code again then you will most likely need to replace them.