Hey everyone. I am a newbie to the site and I have never worked on a Nissan before. Most of the wrenching I have done has been on American cars. Anyway to make a long story short my brother owns a Nissan Sentra. It's a '96 and it is the absolute base model. The check engine light came on and he brought it to the shop. They said it was the oxygen sensor (they didn't mention which one) and they said it would be $250 to replace b/c it's an expensive part and it is hard to get to. Anyway, I looked up the part at autozone and they are only about $50 per oxygen sensor. My question is how many oxygen sensors are on the car. I assume two but I am used to seeing 3 on the V8's I have worked on. With a 4 cyl though I wouldn't imagine that you would need more than two. Anyway, how many are there and how hard are they to replace? I want to help him save a few bucks by doing the work myself. Thanks!

 

there are 2 one is on the exhaust manifold and 2nd is on the cat.

OBDII - 2 oxy sensors
OBDI - 1 oxy sensor

 

theyre not hard to replace. Is a matter of just unbuckling or pulling the sensor out by pressing a little button thingy on the sensor.