Keith R

Hi I am new to this site and was wondering if anybody on here knows about Oxygen Sensors I need to replace one of them but I was wondering if they are all the same and if anybody knows how many there are any suggestions would be helpful oh yeah it is an 03 Suburban that I am driving.

Thank You,
Keith R

maxxman04

ok, first, we need to know what engine you have? i'll assume the 5.3L. your truck has 4 oxygen sensors. 2 before the cat converter, 2 after cat converter. the two before cat read the amount of air and gas in the exhaust. this info is sent to the ecm so that the proper air/fuel ratio can be set. sensors do wear out, which can cause poor idle, poor driving, poor fuel economy. it's recommended every 50k miles they be changed. there are also two after the cat converter that tell the ecm how well the cat is doing it's job. these are recommended to be changed every 100k miles. o2 sensors look like big spark plugs with 3-4 wires coming out.

nyauto

If they fail your engine light will come on and if you go into a auto shop they can check the codes and tell you which one of them failed. they are not hard to replace.

Keith R

Thank you for your help and yes you are right it is the 5.3L that I have I was told there was 4 sensors but wasnt sure if I believed them.

73shark

Keith R: Welcome to the forum.

If you're planning on doing it yourself, get the special deep socket w/ the slot on the side to remove/replace the sensors. While they're not hard to replace, sometimes their location makes it difficult.