shitty gas mileage in automatic awd

[turbo_lag92]

so my car is a auto awd. i get about 150 miles to a tank. i have put new plugs and wires and air filter in the car. and it still gets horrible mileage. any other ideas. i was gonna try a fuel filter and a oil change but i dont think that would fix it much more

 

[livedsm4g63]

O2 may be bad. I've read that sometimes it wont throw a code. Any way of logging?

 

[turbo_lag92]

no i have not bought a logger yet

 

[95blackGsTurbo]

Your o2 is going to be the biggest factor in gas mileage. If a plug a wire is bad or even a fuel filter, it will noticably affect how the car runs. An o2 will just suck away at your mileage and all the car to run rich.

 

[SrKegler]

Do you have a check engine light? Mine was only getting 17 MPG, bought a logger, traced the problem down to blown sensor grounds in the ECU. I now get 28 MPG. Pays for itself in about one long trip.

 

[turbo_lag92]

no check engine lights at all. so what did you do just replace the ecu?

 

[SrKegler]

In my case I was throwing 3 codes. 12-13 & 21. I was also getting the CEL. Doubt if the computer is your problem.

 

[tallywacker]

no check engine lights at all. so what did you do just replace the ecu?

No don't do that. One do you even know if your check engine light bulb works? Want you should do is buy a cheap palm and use some of the free logger software. You need to know what is wrong with your car before you start throwing parts at it.

 

[turbo_lag92]

ya i know it works because it has showed up before but hasnt come back on for awhile

 

[knochgoon24]

I'd suggest replacing the o2 sensor. It's gone lame.

It is the leading causes of poor gas mileage in our cars. Well, other than being to heavy on the gas all the time.

 

[90on35psi]

Yeah man, bad O2 will cause mileage to drop and the car will run pig rich. Definately, if you haven't changed it before, you might as well now.

 

[turbo_lag92]

thanks for all the input guys. later this week il get a new o2 and try it out and hope for the best

 

[ThomasG-1b]

Bad plugs, wires, low tire pressure, bad inj, bad o2 can all lead up to poor mpg's. I get about 20mpg in my 92 turbo awd thats with a heavy foot. And I know it runs pig rich.

 

[jwahl16]

I have the same deal, 95 auto gsx. Replaced everything fuel related. Still get about 16 mpgs. I have a big o2 housing that goes to stock exhaust so I just bought a 3" turboback (to replace my clogged cat) that I plan to get in next week. Hopefully that will help out a little, o and the power will be nice too

Good luck though, It's probably your o2 sensor, especially if it hasn't been replaced before.

 

[feardafish]

A boost leak would cause you to run pretty rich too right?

 

[wkmitsu]

BOV not being recirculated will lower your gas mileage as well, so if it isn't, I would fix that.

 

[jwahl16]

A boost leak and bov not recirculated would cause poor mpgs as well. A small boost leak won't affect mpg that much though. But he should definitely do a boost leak test as well. Vacuum at idle should be around 18-20 inHg