http://www.professionalequipment.com...qx/default.htm
heres the one I use...(ABOVE)...now ILL grant you , that you can buy a whole lot cheaper tool for checking tires, but I use mine basically for reading header temps, to detect mixture or ignition problems or missing cylinders and you may not want to spend the money,
heres a cheap one (below)
http://www.professionalequipment.com...qx/default.htm
heres a far better one but still less expensive
(below)
http://www.professionalequipment.com...qx/default.htm
at times they are WELL WORTH THE MONEY in lowering the time and effort required in diagnoseing problems, and yeah! you do get what you PAID FOR in the better models