If your check-engine light is, something is wrong. This is a no brainer. But it can be easy to forget what a benefit it is to have your vehicle's electronic control unit (ECU) always scanning input from sensors to make sure the engine and related systems are up to par.

Yes, the check-engine light "knows" when something is amiss. The problem is that some people choose to ignore it, saying the cause is just "pollution-related stuff" or, worse, they hear from someone at a shop that "it's not important". When I hear that, I know that particular shop didn't have the expertise to fix the problem.

One of the problems of driving with a check-engine light on is that the light doesn't get any brighter, or start blinking to alert you that something very bad is going to happen. It only has one communication mode: light on. And as long as it is on, the ECU can be storing many fault codes, some of which can indicate a very big problem.

Of all the advanced training I send my technicians to, about 50 percent preates to diagnosing and repairing problems that drivers can be alerted to by the check-engine system.

Fully enhanced scanners which are vehicle-specific cost upward of $10,000 with monthly costs for updates. Between my shops, I have more that $35,000 invested in scanners.

The ECU uses inputs from many components to adjust the air-fuel mixture so that it fires correctly. The ECU's greatest ability is it's self-policing. It checks the amount of air coming into the engine, burns it, then takes samples after it leaves the engine to make sure the air and fuel are being burned correctly. It looks for misfires in the engine and if there are any, it activates the check-engine light. On newer vehicles, it will even report the number of misfires, at what RPM and on what date each happened.

So if you have been told you don't need to worry about your check-engine light, that is incorrect. It can be a difficult system to repair, but it must be to keep your vehicle from breaking down and to protect our air.

Motor vehicles are the No. 1 cause of air pollution in Lane County and Oregon. According to the Oregon Department of Environmental Quality (DEQ), vehicles in Oregon produce more than 119 million pounds of air pollution consisting of carbon monoxide, carbon dioxide, benzene and smog-producing hydrocarbons, nitrogen oxides and other air toxins each day. Traffic congestion and air pollution will only increase as the population of Lane County continues to grow.

High cost of procrastination

We had a nicer German vehicle that came into the shop last month with its check-engine light illuminated. In interviewing that customer, we learned that the light had been on for some time. Money, fear of the unknown and lack of time were reasons given for the procrastination. The car ws running very poorly by then, the engine shaking and producing little power.

The first order of business was to hook up the scanner to find what fault codes had been stored. The list was long and filled with mostly engine misfire codes - an indication that the air/fuel mixture is not being efficiently fired in the engine.

When this happens, extra fuel enters the exhaust system into a device called the catalytic converter. The catalytic converter's job is to convert harmful engine exhaust byproducts into less-harmful byproducts. In a nutshell, it helps keep the air clean so we all can breathe better.

In this case, the overwhelming amount of raw fuel entering the catalytic converters had overworked them to the extent they actually had a meltdown. The honeycomb passageways through the catalytic converter had closed off and were not allowing the engine to breath. This was a major reason for the lack of power.

This vehicle has two catalytic converters, each one costing more than $1000. Wow-that's more than $2000 for just parts in this example of how not to make good use of your money. OK, that's a kind way of saying throwing your money away.

The moral of this story is that most times, procrastinating on needed vehicle repairs or maintenance will cost you more money in the short run. Take the time and money to keep your vehicle in top repair; the investment will pay off in the form of a dependable vehicle.

Keep brake fluid fresh

Changing brake fluid every two years is important for keeping your brakes working properly. Brake fluid is hygroscopic, meaning it absorbs water. And water in brake fluid can corrode brake parts and lower the boiling point of the fluid. If the fluid boils, brake performance will be greatly reduced.

Registration, insurance reminder

Be sure to have your vehicle registration and insurance card in your vehicle at all times when driving. If you are pulled over, you can get a ticket or, worse yet, have your car impounded if you don't have proof of insurance.