oxygen sensor question

[PEGGER]

Hi guys, I'm experiencing what I think is very poor fuel economy in my 1998 Blazer. I'm getting about 350 kms per tank when driving very verylightly. It says on some websites i've checked that I should be getting around 300 miles per tank on average, which is considerably more. My check engine light is on right now and I've run a scan on it, I need to replace my O2 sensor, bank 1 sensor 3. I've done alot of research on O2 sensors and I've come to understand that bank 1 sensor 3 is the only sensor after the cat and that this sensor has nothing to do with the control of fuel, as the other sensors do. I was certain that this O2 sensor triggering my check engine light was my fuel economy problem until I found this out. Could bank 1 sensor 3 still result in very poor fuel economy?? If not what sort of problems would that sensor cause??

[pquada]

Well dude, its worth the $200 it costs ya for 4 o2 sensors. i had the same problem, if you have anything over 75k miles you should replacet them all at the same time., i was getting 10 miles per gallon. I replaced them all and got a k & n air filter now im getting 17 mpg. only one of them is a biot*h and the rest are easy. Actually start with that then do a regular maintenance on it. plugs, cap, rotor, wires, belt. ALL OEM. dont use the aftermarket crap. it sucks. you may end up paying a pretty extra penny for the stuff but it will last longer and work correctly. thats just my

[Jeremy-WI]

You might want to do a fuel pressure test and see if the pressure leaks down after the pump quits(just turn the ignition switch on, engine off). If it leaks down, do the test again with the return fuel line crimped shut, if it doesn't leak down its time for a new fuel pressure regulator