My '96 Blazer has the trouble code of P0153 - "O2 Sensor Circuit Slow Response (Bank 2 - Sensor 1)". It supposedly (Haynes) is after the Cat. I was wondering if anybody has some more information on this. Haynes Manual lists some ways to check it. Is this something I should immediately replace?
It sounds like the heater went out in the sensor causing it not to heat up quick enough and setting a code. I would have the code cleared, and if it comes back immediately, change the sensor. Saw this a lot at the dealer. Hope this is helpful.