what are the chances on a bad 02 sensor no cel?
if is bad or runing rich/lean does it always trigers cel?

 

A lazy O2 sensor may not trigger the CEL, but you have more problems than just a lazy O2 sensor if you are getting 10mpg (from your other thread).

 

i dont know what to start from ? this $3.00+ a gal is killing me big time

 

It's a little difficult to track what has been suggested and tried so far since you started a new thread... but are there any codes stored in the ECU? Did you go to Autozone and have them retrieve the codes?

 

no codes i had a problem with egr but i got that fixed my mechanic told me i am using so much gas bc my egr wasnt working now i got that fixed still same problem time that i had problem with egr after reseting ecu cel would come up after like 10 min of driving now i am driving for like a week no cel

 

Try to test your mileage in the city vs the hwy. Your hwy mileage if you are cruising around 60-65 should be almost 30mpg. If that is the case, but your city mileage is low(10-18) then you might have lazy o2 sensors. The sensors aren't sending the right info to the ecu until they have been running a while. Thus bad MPG. I changed mine for that reason and restored my overall mileage to 25 including city driving. JMHO

 

is there a way to test them ?

 

well i had 05 03 right bank o2 sensor for almost a year, and then when I got around to replacing it i rechecked the codes and it was gone ? i replaced it anyway but had no explanation as to why the codes no longer showed.

 

i see but is there like a way to check them some how

 

If you have 100k miles on your sensors, it probably time to change them!!

 

i had front right one and back sensor changed only left one is old well i dont know how old i only have this car for like 2 1/2 years so i dont know

 

How many miles on your 96?

 

The rear o2 sensor doesn't affect your mileage. The 2 front sensors will give you bad mileage if old. I would just change the other front o2 sensor and start fresh!! Gas is expensive.

 

about 122k

 

thanx i'll do that
o and one more thing is there a big diff oem or aftermarket 02

 

get a Bosch OEM equivalent from www.oxygensensors.com - $70

 

thats each right
how about from dealership how much they go for?

 

yes, 70 bucks each, as opposed to 120-180 depending on which dealer you go to (online, local, etc.).