HI I have a 1992 4Runner 3.0l 5 speed the other morning started up but would rev over 2000rmp The computer is giving 3 trouble code 21 24 32 i replaced the afm and o2

 

Did you reset the ECU?

Does it too out at 2000rpm in neutral or when driving?

When was the last time it ran well? Did anything happen between then and now? Parts get wet? Fuel up (possibly bad gas)? Run really low on gas?

 

I know you're posting this from a phone, but it's important to include all the WORDS or we don't know what you're saying.

First, it's not in "limp" mode (that's a feature of code 52). Second, code 21 is a fault in the O2 sensor heater CIRCUIT. It doesn't hurt to replace the O2 sensor, but there's a good chance that your problem is actually in the harness (which is exposed under the truck). Get out your multimeter and check voltages: http://web.archive.org/web/201003261...01heatedox.pdf

I assume you had all three codes, replaced the O2 sensor and the VAF on a whim, and still have the same three codes. Codes 24 and 32 point to unrelated systems; the only thing they have in common is the CONNECTOR. Check that. And in case you didn't figure it out already:

I'm going to guess there was nothing wrong with your VAF anyway (how much did you pay for the replacement?), so check it too:
http://web.archive.org/web/201003261...92volumeai.pdf