Jakeepoo3
New member
.When you say 'diy tune' I imagine some guy in a street race-esque early 90's Civic with a laptop going 200 down the interstate haha. What exactly does it look like to diy tune a 4runner? I'm almost certain I don't have the expertise or knowledge to pull something like that off.
Pretty much like you imagined. You need a driver to run through all the gears and do 0-60's and all that type stuff while you're watching live data from all the sensors related to the engines timing and a/f ratio. MAF, outside air temp, IAC, throttle position, up and downstream 02s, etc. They all talk to each other to determine how much fuel to inject and when to spark it most efficiently. The factory ECU has set value parameters for these sensors. You basically need to relearn your ECU manually because you're operating outside the parameters of what the ECU expects from certain sensors. You need to research it if you want to diy. You could write a book on this subject. If not take it to a good reputable Dyno tune shop. Shop is expensive and only does it once. DIY you can keep adding aftermarket goodies and can fine tune yourself in real driving conditions that affect the fluid physics of air like temperature, mass, and density I reckon. I recommend wideband a/f sensors instead of dummies before tuning with headers especially if you take it to a shop. There's not really any sense in doing any upgrades like that until your ECU allows the upgrade to do what is designed to do. I want to here the difference in your idle!!