Dear Tom and Ray:

We live in Buffalo, N.Y., and our son will be living and attending graduate school in Glendale, Ariz. He owns a 2000 Ford Contour. We are having it transported out there. From what I have learned, his car will have to pass an emissions test once he is out there. With the car being so old, we are concerned that it might not pass.

Is there anything we can do before we go through the expense of transporting his car to Arizona to determine if we will have to put money into it to meet Arizona's emissions standards?

-- Richard

TOM: Absolutely.

RAY: Does this involve taping a Benjamin Franklin to the underside of the registration?

TOM: No, this is legit. For cars that are model year 1996 and later, the emissions inspection is done by computer. You can have the same test done locally before you ship the car.

RAY: All 1996 and later cars have a system called OBD II. That stands for On Board Diagnostics ... uh, Two! This is the second generation of OBD. OBD is a system of monitors that continuously check things that relate to a car's emissions -- things like the catalytic converter, whether the engine is misfiring and whether the fuel-tank vapor-recovery system is keeping gas fumes from leaking out into the air.

TOM: If anything that affects the car's emissions is not working correctly, that monitor will tell the computer, and the computer will command the Check Engine light (also known as the MIL -- Malfunction Indicator Light) to light up on your dashboard.

RAY: So if the Check Engine light is off and the car's monitors all report that they are "ready," then your car will pass that part of the emissions test.

TOM: You can have that stuff checked at any repair shop that has a scan tool, which almost every shop has these days. They simply plug their scan tool into your car's OBD port, and it gives them a readout. If the readout says "monitors ready" and the Check Engine light is off, you're good to go in New York or Arizona.

RAY: Actually, they allow you to pass even if you have one monitor that is not "ready." For instance, one thing that's monitored is the fuel-tank pressure. The tank is supposed to be able to hold pressure rather than release gasoline fumes to the environment. But if you just refueled the car, that monitor may show "not ready." So the one monitor exception is designed to give you a pass on reasonable faults.

TOM: The second part of Arizona's emissions test just checks your gas cap, to make sure it holds pressure. Your local garage can check that, too.

RAY: Keep in mind, though, that one thing that leads to emissions-test failures is a dead battery. If your battery dies, or it is disconnected while the car is being shipped, all of the information in the OBD II system will be wiped out. That means you'll need to drive the car 25 or 30 miles, with enough restarts, for the OBD system to collect enough data to be able to report again.

TOM: But other than that, if it passes the OBD II in New York, it should pass in Arizona, too.