I'm not really a car person, but I'm trying to find out where the oxygen sensor is on my 2003 Acura TL, the one located before the catalytic converter. Does anyone know where I should be looking for it? Also, are there one or two of them? Thanks for your help!

 

There are 2 of them. One is located on the header just after the 2 banks merge. That is the Primary or #1 sensor. The one at the cat is the 2ndary or Bank #2 sensor. You will have to be under the car for both.