O2 sensor
 

What does the o2 sensor do. i put new exhaust on my trucj and the garage said it isnt nessisary to put it on
thanks

Measure the air/fuel ratio for your truck. The fronts do anyways. The rears make sure the cats are workin correctly. you don't absolutely need the rear o2s but will throw a SES light without a tune

zraddy,

I am a Product Specialist with Walker Products, a manufacturer and worldwide distributor of oxygen sensors. As country said, the oxygen sensor's purpose it so monitor the air/fuel ratio in your exhaust. The benefit of this to you is healthy, smooth running engine with optimum fuel efficiency. You could certainly do without these things if that were your choice. However, if your truck is a modern vehicle then you will get a CEL due to the missing sensors. What exactly do you drive?

Country hit it right on the head. The fronts (between the exhaust manifold and cat) measure the air/fuel ration and the computer adjusts accordingly to those two. The rears (just after the cat) measure the temp of the cat and make sure they are working correctly. IF your exhaust deleted the cat and/or these last two O2 sensors, you WILL need a custom tune to resolve your problem

Hope this helps

Eric

the only thing an oxygen sensor can measure is oxygen content.

in reguards to the catalytic convertor; the ecm compares the cross counts (lean to rich transitions) of the front and rear sensors to determine if the catalytic convertor is functioning (oxidizing hydrocarbons in the exhaust stream).

if you want to add the o2 sensors to the new exhaust; threaded fittings are available that can be welded into place.

my truck doesnt have the cat converter or the 02 sensor just cut them off while putting new exhaust on

Yeah man, your going to need a custom tune with the rear o2 sensors deleted. This will be needed to turn off the infernal check - engine light

What year is the truck. You must have them if the truck is OBDII. If it is not you should have them but could get away without even though I would recommend not to.

Its a 1995 k1500 with a v8 350 in it.
What does OBDII mean ???

OnBoard Diagnostic 2