Nick Lynch
Bolt pattern and torque specs are here: http://toyota.offroadforum.cz/aarc.epnet.com/application/8578/8578R03_Cylinder_Head.html
The arrangement is the common four-in-line cylinder engine. number one is in the front and the firing order on the dist cap is 1-3-4-2
Could be any number of things, from an open gas cap to a short in the ignition system, etc. Take the truck to someone who can scan the code.
There are 2 one on the bottom easy to see and access. The other is on the top hard to see and access. You will need about a 12 inch's worth of extension to make it easier. Good Luck and...