Had the code checked at AutoZone. PO161. Anyone know the approx. cost of replacing this O2 sensor ("malfunction exists in the heater circuit for o2 sensor") Is this an O2 sensor replacement or something esle?
Sounds like you need an O2 sensor. Most people replace them in pairs, because the other one next to the bad one will likely die soon as well. No idea on price, call some dealerships or check with parts stores for pricing.