Hello
I've got a 99 ranger 3.0 flex 4wd with M5OD-R1 5-speed. When I was out driving, it seemed to be sluggish getting up to speed. Noticed it at slower speeds when in 3rd gear going up a hill and again in 4th. I was on a local interstate. It was sluggish when I got up to 45-50 in 4th. When I shifted into 5th gear still felt slow to gain speed, but when it got up to 65-70 mph it drove great. Any thoughts? Should ichange out the transmission fluid? Or is the engine or transmission failing? I want to get this truck running good and safe for son. I know she's old but it's a good truck.

 

Could be a few things, well quite a few, lol

When did you last get gas?
Did you notice the issue after that?
Higher ethanol fuel has less power

Check throttle cable
Engine OFF
press gas pedal down to floor and hold it down with a stick on drivers seat or ??
Then open the hood and see if you can open the throttle more manually, if so then throttle cable is stretched, easy fix for that
Google: Ranger throttle cable mod

Clean MAF sensor, should be done once a year, easy to do

Test engine with a vacuum gauge, $20, and test if engine has good vacuum at idle 18-21"
Then do blip test for exhaust blockage

Read here for vacuum tests to do: https://www.gregsengine.com/using-a-vacuum-gauge.html

Upstream O2 sensors are only good for 100k miles, how many miles on yours?
Replace both upstream O2 sensors if your not sure, you also get better MPG so they pay for themselves over the next 100k miles


Also I assume the CEL(check engine light) works, comes on with key on and goes off after engine starts?
If not then you may have some trouble codes you are not aware of, and a burned out CEL bulb

 

My son filled the truck up about a week ago. 87 octain. Check engine light works like it should. The truck has 152K on it. I noticed the issue before he filled up. We're going to be changing the oil + filter, air & fuel filter, oil pressure switch this weekend. I'll check the throttle cable when we're working on it.
thanks