The front ones are the ones the PCM uses to control air fuel mix, im pretty sure of, the rear ones monitor the cat's effeciency. However, not sure what effect it will have if they arent bypassed or programmed out. PM Camaro 69 or craby , they know.

 

if the ecm has not been tuned then the ses light should come on. other than that not having rear 02s will not do anything. you will fail any emissions checks though. you should at least take the front two out to see if there fouled. you can clean them by heating them up with a butane torch.

 

Unless you changed things, the 99 comes with both upstream and downstream O2 sensors. The downstream sensors do not affect performance. My be that your car is upset because you gave it a girlie name.

 

^ lol. Yeah that's it, cars do hold grudges!

 

Lol! Rear O2s shouldn't cause these syndromes. And yes the SES light is always on b/c of it. And btw, all of my vehicles have female names. lol

 

And they all probably act like one when you least expect it. All my cars have gender neutral names, like POS, rust heap, pile of junk, sh** box, etc. You got to put fear in them and show them who' s boss, and let them know the junk yard is close by if they act up. Also can't be accused of sexually harssing the car.

 

The O2 sensors are kinds strange in what they can do for your car. If they are completely out of range the CEL will be on and the car will stay running in open loop, not taking the full data into the computer for optimum performance, this can cause drivability issues, as well as loss of performance and mileage. The O2 sensors that are not totally out of range can cause lagging, sluggish starts, poor mileage, too rich/lean mixture and afew other symptoms. They should not cause a car to want to die since the car should run in open loop. The rear sensor is mainly there to check for catylist effeciency and function. This sensor does not have anything to do with mixture nor will this sensor put the car into open loop ( or limp home mode). Now having the CEL on at all times could be bad... you may have a new code that you dont know about that is causing the dieing issue. Also some codes come up and if not addressed soon engine damage could occure.

Massey

 

Thanks man! You are awesome! You know everything Lol! Yeah, I plan to plug up my diagnostic and see what codes I have, and when I get the money I plan to send off my computer and get the rear O2s deleted. But that's $250 so I'll have to wait a little bit. But that way I can have them deleted and then the SES will be off, unless something else throws a code.
Again Thanks man! I'm gonna check it tomorrow as soon as I possibly can!