Do our cars have somekind of air/fuel ratio sensor in them?

[Polak420]

I'm trying to figure out why my car is getting very low gas mileage. (bout 165 miles on a full tank) My O2 sensor is fine. Not sure yet if I have a vaccum leak. I have 42# injectors with the pressure set at 42 psi.

 

[zam70]

The O2 sensor IS the fuel air mixture sensor.

 

[d0n_3d]

ANY kind of exhaust or vacuum leak will kill gas mileage...be certain you have none...also just because the O2 sensor isn't throwing a code doesn't mean it is good...make sure that thing is fresh and it's a OEM ac delco sensor with the purple wire...not the crappy Bosch sensor...also make sure the chip was programmed correctly for the injectors you have and the combo...

 

[d0n_3d]

hey I just noticed you are from Merrillville, Indiana!!! that is like not even 10 miles from me...shoot me an email sometime....maybe we can meet up?

d0n3d@comcast.net

 

[Polak420]

The O2 sensor I have is the Heated O2 sensor kit from Jay's GN. It is about a year old. I also got my injectors +chip as part of a package deal from him so I'm pretty sure they are the right ones. What is the best way to check for vaccum leaks in our cars.

 

[d0n_3d]

checking for vacuum leaks can be quite tricky...go through all your vacuum lines and inspect them visually...get a can of carb cleaner and while the engine is running spray (within reason) any vacuum line connections you can get to, if the idle suddenly jumps up then you have found a leak...sprayaround the throttle body and plenum/intake area...

as for header leaks or exhaust leaks, look around for cracks and look for black/white soot in cracks and double check all connections...

the heated o2 sensor you have is fine...no problems with that