2000 Villager poor fuel economy.

[curby_13]

I just purchased a used 2000 villager sport with 77k miles on it. I filled it up after purchase. I noticed after that I had only gone 178 miles and gone through 3/4 of the tank. I replaced a faulty O2 sensor(bank1 sensor2). That improved the fuel economy slightly. I did a tune up this weekend. The mileage is still poor. I hope somebody can help me in the right direction.

[mcmalloy]

Cat could be plugged, or maybe a sticky rear brake, does it coast good if you put it in neutral while your driving or does it slow down quick

[tempfixit]

Was this city driving or highway driving??? Did you have a code for a faulty 02 sensor??? The precat sensor is the one that tells the pcm to richen or lean out the fuel/air ratio not the after cat sensor. If any codes what were they???? Are you carrying tools or extra weight in the vehicle??? Have you added any injector cleaner to the gas. What condition is the air filter in?? Have you cleaned the MAF sensor???

[curby_13]

Originally Posted by mcmalloy

Cat could be plugged, or maybe a sticky rear brake, does it coast good if you put it in neutral while your driving or does it slow down quick

Vehicle does coast fine. I'll have to keep the cat as a possibility.

[curby_13]

Originally Posted by tempfixit

Was this city driving or highway driving??? Did you have a code for a faulty 02 sensor??? The precat sensor is the one that tells the pcm to richen or lean out the fuel/air ratio not the after cat sensor. If any codes what were they???? Are you carrying tools or extra weight in the vehicle??? Have you added any injector cleaner to the gas. What condition is the air filter in?? Have you cleaned the MAF sensor???

Driving was highway and city. I got the knock sensor code, but engine light never came on. Also the code is intermittent. I know not to touch the knock sensor. No extra weight in vehicle. Just got the tune up and added injector cleaner right after. Air filter is new. I haven't touched the MAF sensor yet.

I found and old post from IH8SPM where he had the exact fuel economy going. Wondering if anyone knows what he did to get it resolved?

[tempfixit]

What kind of spark plugs did you install??? I would clean the Maf sensor and if possible hook up a scanner that you can watch how the prercat 02 sensor are working, if they are lazy you will get poor mileage. The rear 02 tells the pcm how the cat and precat sensors are working by detecting carbon monoxide and hydrcarbons.

If you remove the precat sensors and the cat is plugged the vehicle will run much better, you could also disconnect the precat sensor and see if that makes a difference in mileage as the pcm will set to default fuel air mixture.

[curby_13]

Originally Posted by tempfixit

What kind of spark plugs did you install??? I would clean the Maf sensor and if possible hook up a scanner that you can watch how the prercat 02 sensor are working, if they are lazy you will get poor mileage. The rear 02 tells the pcm how the cat and precat sensors are working by detecting carbon monoxide and hydrcarbons.

If you remove the precat sensors and the cat is plugged the vehicle will run much better, you could also disconnect the precat sensor and see if that makes a difference in mileage as the pcm will set to default fuel air mixture.

We installed OEM spark plugs. The Pre cat sensor was replaced by the dealership before we bought it. The post cat I had changed.

[tempfixit]

Have you checked the fuel pressure regulator line for gasoline in it??

[curby_13]

Originally Posted by tempfixit

Have you checked the fuel pressure regulator line for gasoline in it??

No haven't checked that.

[drcoffee]

Check the fuel filter under the drivers side sliding door. The rubber hose connections will rot over time and it may be leaking. The only way you can go through 15 gallons of gas in 2 hours is by leakage. If you were burning that much fuel, you would smell the gas at the exhaust and it would be obvious.

[bry11]

I recently bought a 99 villager sport and am having the same issue getting 10 mpg.
I am going to check all your suggestions. Any others?

[tempfixit]

Originally Posted by bry11

I recently bought a 99 villager sport and am having the same issue getting 10 mpg.
I am going to check all your suggestions. Any others?

Do you have a scantool capable of reading fuel trims, if so post them, both STFT and LTFT.

99's are known for bad distributors, if you ever need to replace use a RICHPORTER distributor.

[bry11]

Yes my brother has scanner going to hook up this weekend. Distributer was replaced in june by previous owner. Thank you for help. I will keep updated