Backfires when giving it gas

When I start my 1998 4runner it starts and runs just fine. When you push the gas it will rev all the way out. After about 2 mins running it stays idling just fine but WHEN I GIVE IT GAS it won't rev past 2000rpm. Starts bogging down and back firing what do you guys think the issue is??

I've tried fuel treatment and let's it run 1/4 the fuel it then refilled it. So far

 

Welcome. What engine does it have?

 

My first reaction is to attach an OBD scanner and lookup the diagnostic messages. Have you tried it yet?

 

Yeah, check for codes.

With those kind of symptoms maybe the TPS has gone bad?...the ECU doesn't know where the throttle is? Is there a motor in the Throttle body like on the 2001-2002 that could go bad?

Fuel cleaner isn't going to anything. Something is definitely broken. Cleaning the throttle body might help it, but I think you have to remove that to do a thorough job.

I would also try the carb cleaner trick to find leaking vacuum hoses. Vacuum hose leaks usually cause bad idle and you say that's not the case. I don't know if a vacuum leak could cause the revving out.

Please post back with what you find.

 

MAF - Mass Air Flow sensor. Get some MAF cleaner (yes do not use any other cleaner). Let it dry for a few hours then reinstall. The ECU is not keeping up with idle/throttle while it is running. Yup TPS should be checked as well.

 

my bet is a clogged cat converter.

 

You may want to follow this active thread: https://www.tacomaworld.com/threads/2000-3-4l-v6-4wd-will-not-rev-past-2000-rpm-no-cel-help.705726/