would any of those give me really bad gas mileage.. im getn about 17 mpg at 1/2 to 1/4 i go about 40 45 miles. i put a new air filter in too today.. i haev a code 51 also 96 neon sohc all stock

 

bad o2 sensor would just default to a standard a/f mixture so i doubt its that.

i dunno about the catalytic converter. i dont even know how often those go bad. i pulled mine off my '99 car w 221k miles and it looked pretty good and worked good till i took it off.

 

icic idk what else would b causeing me to have such bad gas mileage...new fuelpump and air filter...its getn to the point that i dotn wanna drive it any more

 

well the pcm controls the timing/mixture. i should say an o2 sensor that ceases to function should default to a standard mix. i guess it could act up and still partially work. it'd be weird though.

does the car feel rich - and does it smoke

or is all the gas just being eaten up really quickly? sure you arent leaking fuel anywhere?

 

no im not leaking fuel anywhere the gas gauge dont move over night or anything when i go start up in the mornings. i did take the fuel line off to c if the car was getn fuel to the fuel rail and there was no fuel cuming in till i found out that it was kinked at the fuel pump. would fuel pressure have anything to do with the fuel problem??? i have a code 51 to if that helps anyone out..

 

[*]51 Oxygen sensor stuck at lean position (Bob Lincoln wrote: may be tripped by a bad MAP sensor system causing a rich condition, and the O2 sensor trying to compensate. The O2 sensor may still be good. The MAP assembly consists of two pieces, the valve and the vacuum transducer (round plastic unit with cylinder on top and both electrical and vacuum connections) - If you get hot rough idle and stalling, especially on deceleration, accompanied by flooded engine and difficulty restarting, that can be a bad MAP sensor causing the O2 sensor to try to compensate. If you get poor cold driveability, stumbling and bucking, and acceptable warm driving with poor gas mileage (a drop of 10 mpg or more), that is usually the O2 sensor. [Webmaster note: MAP sensors seem to die regularly.]

 

i noticed that sometimes whe i get on it in 1st it wont go up to 30 starts at 25 and then i shift and at like 40 45 does it again so im assuming its the o2 sensor.. im getn about 17 mpg. i put n a new pcv today since mine was dirty. next is goin to b o2 sensor or sensors. then the cat.. now sense i put the new pcv in im getn a lil bit more gas mileage. i went 58 miles from 3/4 to 1/2 so thats alot better than 40 no im showing code 12

 

new pvc what?

i told you i thought it was the 02 sensors, same prob w my 95
wen you get a cat, get a high flow one, little more power, better flow rate(obviusly) and a little deeper richer sound

my buddy bought the magnaflow one fomr modern and didnt want it and he sold it to me for 4 bucks, brand new
i love it

 

if to o2 sensor is bad yes it will mess up your gas milageand same goes with the cat

 

"code 12 Battery or computer recently disconnected (will occur on most cars most of the time, it indicates a low / missing battery happened in the last 50 key starts. Don't worry about it. —Tom Wand)"