4Runner seems to have lost some horsepower possibly

[stevew092984]

Hey guys, I’ve got a 98 runner 3.4l V6 and when I’m on the freeway and there’s any kind of incline, my 4Runner seems to be struggling keeping speed (around 70mph). I’ll have to push the gas and the engine will drop down to a lower gear and rev up to like 3500 rpm’s. Didn’t used to do that. I’ve got a few ideas what I can do, but wanted to check here first to see if anybody had any ideas what may be causing this. Thanks

 

[pluton]

You've already ruled out:
Low tire pressure.
Front alignment off.
Extra weight in vehicle.
75W-140 gear oil in the rear diff.
Clogged air filter.
Clogged cat?

 

[3bears]

I bought a 4runner that when test drove, ran great, but test drive was all on flats, when I went to go home when it hit the hills it was gutless.
went to do a compression test and pulled out plugs, single electrode ac plugs, did the compression test, was good, new plugs, cleaned maf
and throttle body, changed fuel filter and air filter. Problem gone, dont know what fixed it. Now that 4runner is gone, it was a POS but got me through the winter snow and ice, did the andy mod to it