My 90 4runner with 56k has a problem
I noticed that my gas milage has gotten worst over the year I get about 200 miles on a fulltank. Yesterday I went full tank and traveled 70 miles after and my meter went a quarter down. what is the problem? is it the o2 sensor?. For the past 2 years I have also notices layers of soot or that black stuff on my tailpipe.

Anybody with the same problem?

 

70 miles per quarter tank? Thats about normal.....

 

what about soot on my tailpipe?

 

All exhaust pipes will have some but its not suposed to be really heavy.

 

Tire pressure?

 

Might see if there are any stored trouble codes in ECU:
- http://www.4crawler.com/4x4/CheapTri...CheckConnector

And O2 sensors do get tired over the years. If yours is on unknown vintage or mfg., might be worth replacing:
- http://www.densoproducts.com/

 

70 mi to the quarter tank is pretty decent. In the city, I get 60mi to the 1/4 tank with the 4 cyl motor. 200 mi to a full tank seems a little low though.

My exhaust pipe is lined with soot, every exhaust pipe I've ever looked down is.

 

70 to a quarter is about what I got with my '93 p/u. With the new runner I went about 320 miles on the tank, thats 96.27963% city, a short trail trip with 4 lo up a long hill, and aggressive driving. It was actually probably less because I have 31x10.5s on 4.10s. but still

 

I guess my problem aint that bad. But my o2 sensor has to be changed. Thanks 4crawler for the Denso recommendation and link

 

56k is REALLY low mileage~

If the O2 sensor doesn't fix it for you, repost in this link & we'll try to help you out.

Rich mixture & crappy fuel mileage can also be caused by old/worn plugs, wires, distributor parts, etc.

 

Also check that your brakes are not dragging. I was getting bad milage for a long time that I found that my master cylinder was going bad, aslo one of my calipers was half seized. (2 of the 4 pistons were stuck and dragging)