1998 toyota t100 the check engine light is on

SOURCE: 1998 Toyota Avalon Check engine light

should have an OBDII connection under the dash on the drivers side. Looks like an elongated computer port, probably has a cover on it that says OBDII. You can buy a code reader from an auto store like pepboys for around $100 i think. Just a side note, usually if the car is still driving ok and not acting weird, it is an emissions sensor.

SOURCE: how to replace ignition for 1998 toyota t100

Pull off lower panel pieces right under steering wheel. The panel should be held in by screws or 10mm bolts. Then turn the key to acc position and then underneath the ignition you should see what looks like a little brass button in a hole. Push this button and then pull out the ignition cylinder with the key.

SOURCE: I have a 1998 toyota T100 pickup truck automatic

well if you have a light that goes on and off that could be a EGR valve or bad o2 senor.

SOURCE: 1996 Toyota t100 check engine

What codes do you have?
You start with the check light issues first

I just parted with a truck, I had over 18 years with OE Plug wires,
one before 17 years ,and my current one, 20 years,I have owned it 27
Had one wire burn out near plug in 1990

Plugs never misfire by design,they do however wear the electrodes,
which stresses ignition modules

SOURCE: 1998 Toyota T100 Should I

Wow, thats alot of miles! How well does it run? Hopefully you have record of the parts that have been replaced allready. You could replace the engine with a new one, but how many miles are on the transmission, injectors, sensors, differentials, ect..? Maybe you could buy a wrecked truck with low miles, transfer most of the drivetrain and drive it another 500 k. The way I see it, if you invest $2,000.00 into the truck and can drive it for two years without any more major investments / repairs, you will have invested well...I hope this helps.