I have a 98 Ltd with 130k on it, i have recently been getting a constant downgrade in fuel mileage, i have also heard that the o2 sensors on 4runners start to fail around now, would those be a big factor in losing the mileage? how much are they to fix?

 

yes they well make your gas mileage go down there not that hard to do https://www.yotatech.com/forums/showthread.php?t=39653 order a new one from www.urdusa.com

 

How Many do 4Runners have?

 

it has two the rear one rarely fails

 

Be sure to only use NGK (actually, box will say NTK) or Denso. Do NOT use Bosch (they're a fine product, they just don't work well in our trucks).

You can have a bad O2 and it not throw a CEL. As they degrade, they will err towards running rich and your fuel economy will suffer.

I just replaced mine, it was about $85 from Summit Racing.

 

thanks, a lot ill look into replacing one and we'll see from there.