Where do I find the O2 Sensor on my....?

Question

2003 Chevy 2500 Cargo Van. 4.3 liter

Answer 1

You have one on either side of engine on the exhaust manifold and then there is one after the catalyic converter.

Answer 2

There should be two. In the exhaust plumbing. One of them will be "before the cat"(alytic converter) and the other "after the cat". The before-the-cat one will be on the exhaust manifold or in the exhaust header/pipe. The after-cat one will be ... you guessed it... right after the cat.

They should be conspicuous in that they're the only things on the exhaust piping with wires sticking out.

Check your service manual but it may be correct to change them out together as a pair. The purpose of the oxygen sensor is to calibrate the fuel injection system. The purpose of two oxygen sensors is to test whether the catalytic converter(s) are working.

It's not unusual for oxygen sensors to go out. In the 80's they said change them every 60,000 miles. Now the computer can detect when they've failed, so they just say change them then.

Answer 3

i own a shop,an if you,ll look on the exhaust pipe a few feet down from the manifold you,ll see it there on the pipe it screws in,and this one might be located closer up also,where the pipe joins to the manifold pipe,but you,ll see it there,good luck hope this helps.,,PS on this one there may be two on it,usually on heavy duty trucks they didn't put the full smog package on them.

Answer 4

it should be on the exhaust pipe,right in front of the cat.