I have a 1995 SC400 whose "check engine" and "trac off" lights have been coming on. After clearing codes and resetting the computer, I jumper TE1 and E1and it throws error code #27, sub O2 sensor.
I have read, the sub sensors are behind the cat converters and rarely go bad (there are two mains and two subs in the 95 SC400). I also read they measure O2 levels in the exhaust gas and determine when you have a failing cat converter. My question is this: Is there additional troubleshooting required to confirm the problem is a faulty sensor? If not, any way of telling which sub sensor is bad?
Mike in Dallas