thought id share something i found on another site, pertains to resetting your air bag light, especially for code 41. this should only apply to obd1 vehicles.
i dont know for fact this will work with the 4runner, but i have a sneaking suspesion that this will work for all obd1 toyotas. this is from a celica site, but it works on 2nd gen mr2s(just did mine today and the diagnostic plug and all terminals are identical between celica,camry,mr2,4runner all obd1. so im willing to bet most of the codes are the same as well. i had my air bag light on for about 6 months now. Nothing was wrong with it, if you pull the instrument cluster will power is still applied in the system, you will get this. the only way to clear it is to do a fsm procedure nicknamed: "playing the drums" where you alternate grounding 2 terminals in the diagnostic port, or you could build this $7 tool that will work as a code flasher, and a code clearer. i dont know it it will flash all codes, or just the airbag, but its usefull none the less. heres the link: pics below are the one i built today.
http://www.toyotacelicaonline.com/airbagtool.htm



edit, obviously the 2nd gen obd1 4runners dont have airbags, what i was going to check is if this works with diagnostic port to flash standard trouble codes, instead of having to sit in the car. just thought id throw this out there, you never know, maybe others here have camrys, mr2s, celicas, corrolla that this may work for.

 

thnx for the link. I'll make that tool tonight and see how it goes. Thnx again.

 

hmm, on my 91 celica the air bag light was on for the year i owned it and the girl i bought it from said it had been on for a couple years before that. i put a used airbag i bought on ebay in and it didn't fix it, the bag was only $5 so that may have been the problem too, but i wasn't out a bunch of money anyway. i ended up just pulling the bulb on the instrument cluster, much like i've done with my ABS light in my 4runner. perhaps i should have tried this, might have solved the problem. good call.