CEL code P0135-025 B1S1
 

Hi!

I've got a 2001 galant VR-G GDI. retrieved the abovementioned Check engine light code. I guess thats something to do with Oxygen sensor.

can anyone help?

If its oxygen sensor, can anyone tell me what can happen if I dont replace it? and if i do, how much it may cost me and whats the parts code number?