I refuse to work on my Dad's Blazer due to the fact that if I do something wrong I'll never hear the end of it. Anyway, he got a CEL the other day for a bad 02 sensor. He took it to the shop and they told him they all responded so they just reset the ECU and sent him away. They also told him that he has 5 O2 sensors and replacing one would be expensive because they'd have to go and locate them all. Is there any truth to this?

I'm sure I didn't get all the facts of the story straight, but I just wanna know if he does in fact have 5 O2 sensors.

 

Five?

probably 3. One on each side of the motor and one after the cat.

 

A 96 should be odb2. The readout should have told them which bank and which side of the cat. Most of the time the problem the computer reads out is the sensor is out of range, not that it gives no reading. I would find 5 sensors hard to believe too.