I was just wondering how many o2 sensors are on our truck. I went to advanced auto(will never go back again). They finally came to the conclusion that it was the upstream o2 sensor. I bought it because i know for a fact it is(Ive gone to orielly and autozone and got the same code but they told me it was o2 sensor)
There are two catalytic converters...I see one after the second one and another inbetween them but cant tell if there is one on the headers or inside the engine bay.