I have a 1999 Chrysler Sebring I put the obdd2 code scanner and pulled the code p0134 o2 sensor bank1 sensor 1. [what the code scanner book says] (haynes manual says upstream o2 sensor) Well I know this car has 3 o2 sensor's on it 1 by the firewall one in front by radator underneath on exhaust pipe then another infront of the convertor so witch one is it? I'm thinking it is the one by the firewall that is in the exhaust manafold but not sure plz help

 

bank one will be the spark plug that is closest to u looking at the engine rule of thumb.

 

Sorry forgot to say the motor is a 2.5L[&o]

 

The bank 1 upstream O2 sensor is the one you can see when you open the hood. It's the easiest to replace. Hopefully, replacing the sensor will cure the problem. If not, then you've got a wiring problem, but a bad sensor is the most likely culprit.

 

My 2.5 (1997) has 4-O2 sensors. Bank one comes from the front of the engine, Bank 2 the back. Each has 2 sensors in them before they join together and head to the converter. The one toward the cylinder head is the upstream in each. The downstream is about 18" toward the converter in each. Therefore, Upstream bank 1 should be the first one you trace coming out of your front 3 cylinders.