My 03evo8 has some idle issues which makes the car shut off during cold starts unless I keep my foot on the gas. I had a tps light come on and I changed that and it is still happening.

Recently this code came up
DTC P0138: Heated Oxygen Sensor Circuit High Voltage [SEMSOR]

I figure it is a bad o2 sensor but if someone can help me out and tell me with one it is and where the best place is to pick up a new o2 sensor id appreciate it.

 

rear


edit:// what are your mods? I may be mistaken, but this shouldn't cause idle issues.

 

i have the same code...its the rear.....i have tp...and had the ext on it for 3 years..all of a sudden my ses is on abou this

 

HO2S S2.
Just patch your ecu to simulate the secondary O2

 

+1