You are driving somewhere when suddenly an icon of your engine turns bright yellow on your dashboard. You don't know what it means. But it looks serious, very serious. That's an outline of your entire engine. It's no t like you only need gas or something. Cars need engines to function and they're expensive to replace. You wonder if your car will explode, or start dropping parts all over the road.
Fear and panic sets in. Gotta get home before something really awful happens as you are doing seventy in the left lane of the freeway.
You drive the car to your favorite service station, and the attendant tells you that he has to do some tests. "Tests????" You find that he has a computer that he attaches to something under the hood, and a tube he puts into the exhaust pipe. Reminds you vaguely of a colonoscopy. People who get colonoscopies are luckier. They are offered drugs. He shoves the tube up the exhaust, and runs the engine. You wince.
"There's nothing wrong with the engine," he tells you. "Your emissions are fine. It's the sensor--the OBD II--that's broken."
Nothing wrong with the engine! Oh, thank you, God! It's over, you think. You breathe easier. You feel lucky. Your car won't need a new engine.
But then the attendant says "You'd better have it taken care of." He sounds serious so you ask: "What will it cost?"
"About seven-hundred and fifty dollars," he says, trying to seem nonchalant. Trying to make it seem like this is a wonderful way to spend your money.
"SEVEN-HUNDRED AND FIFTY DOLLARS????? TO FIX A LIGHT THAT STAYS ON WHEN THE ENGINE IS OK?????"
"I know it's a lot of money," he says. "But the part is very expensive. And if you go to the dealer they are going to charge you twelve-hundred. People are even stealing them from parked cars."