I have a 2000 4Runner Limited with a 3.4L V6. I've been noticing lately that is seems to be running sluggish. Sometimes when I first crank it up cold and pull out of the driveway it will barely go. And on the interstate it seems like it will barely run 70-80 miles an hour. I used to could put the cruise on and it would stay 80 over hills and whatever I would come across. I noticed that when i'm pulling a hill in it it drops down to 65 and if I put the pedal to the floor it will go up to about 3000 and then drop down in rpm until I let the pedal up to a certain height and the rpms will raise back up. I changed the fuel filter thinking that could be the problem and it was pretty stopped up but it still does it. I'm thinking about checking the fuel pressure next. Anybody ever had this problem?

 

how are your plugs? ik my truck ran slow after i rebuilt it and i changed the plugs + wires and it ran great

 

They don't have that many miles. I changed them pretty recently but I'll look into that.

 

make sure the wires are good and the cap

 

When ever I put the pedal to the floor it just doesn't get up and go but whenever I pull the pedal up about an inch it takes off

 

I wanted to update this. It ended up being the Air/Fuel Ratio sensor. It is like an oxygen sensor but this car has california emissions in Alabama. Who knew?

 

That was my first guess after reading your post. Always o2 sensors first on higher mileage/older vehicles