Denver2009

I just picked up a 2002 4runner with 85,000 miles on it and everything runs great as far as I can tell. I took it to two different mechanics before I purchased and both came back with good reports.

I have noticed that when it gets going it it fine, but in lower rpm's and when it changes gears and the rmp's drop the truck drags. Does anyone have a suggestion on what could be causing this or is it just the way it is? I have added cold air intake and a high flow muffler to try and help it breathe, but it wasn't a noticeable difference.

What have you guys/gals done to get the 183 hp. v6 engine up to par?

eddieleephd

I am going to guess that it is an sr5!

I am A manual trans guy however the one thing I can say
is that the sr5 is a long ram intake which are in thier prime
between 3200 and 3600 rpm!

Would actually need alot more info to give any advice on what to do!
such as is it an sr5 how many miles any performance mods other than
prviously stated?

What kind of oil is in it?

all can effect the performance!

Denver2009

Yes I have a SR5 and its an automatic. If I turn O/D off I get some power back, but I would rather just get some low end power in it without having to rely on turning the O/D off.

The oil that is in it is a synthetic 5W-30 for the cold weather here in CO.

Denver2009

No other mods, just air intake and hi-flow muffler.

Looking into other things, but it seems like there isn't an answer or success story that everyone agrees with as far as getting good results from upgrades/mods for the 4runner engine and power.

okie81

SR5 was a trim option.

Depending on the extent of your "hi-flow" muffler, you may be having back pressure issues that may be hampering your low-end torque.

Denver2009

Interesting. Would an engine diagnostics show back pressure and/or other issues? What suggestions would you have for increasing hp, torque and performance?

hross14

There probably isnt a problem and you are just a victim of an automatic transmission . Do some searches and do some reading--there is tons of stuff on here....etc...

pdyebrasil

As of late I have been experiencing the same problem... in the 2000-3000 RPM range my engine drags, and it didn't use to. After reading up on some things I'm going to look into changing out my fuel filter and possibly my TPS. See if that fixes the problem. My MAF and throttle body are spotless, and it seems like those could be the other culprits.

It's hard to tell you what's up though, especially considering you can't compare your experience to a "before" one.

02_Limited

Could be a clogged catalytic converter too? I have noticed a loss of power in that area, and I've had the truck since 2002. 130k and the cat has never been replaced.

Or maybe the 5VZ is a whimpy engine in our 4000+ lb. trucks.

hross14

One thing to remember folks is that all things wear. With a 137k on the odo it is time to start replacing wearable parts....i.e. O2 sensors, TPS, MAF......etc...plugs.....wires. Do those and then start trouble shooting

Denver2009

Thanks for the suggestions, I have my next few weekends full now with all this new info.

CYi5

A TPS should show a code, mine went out last week. You would be able to push the pedal to the floor and it wouldn't go above 2000rpm and your throttle would feel pretty restricted. But it's a $70 if you want to try it.