: 1800x1200 px
: June 20, 2018
An old oxygen sensor (say, 90,000 miles or more) may still work well enough that it doesn’t trigger the check engine light but could still hurt fuel economy. Engine performance can also be reduced by more serious internal problems, such as valves that don’t seat properly or worn piston rings, or by restrictions in the exhaust system. Because the same symptoms can suggest different problems, and there are often several possible causes and cures, it’s better to consult a professional mechanic than to try to be one if you have neither the experience nor the right equipment to diagnose drivability problems. In short, rather than ask for a tune-up, tell a mechanic what you’re experiencing and ask him or her to find the cause.
With ABS, sensors mounted at each wheel monitor the speed at which the wheels are turning. If one is turning slower than the others during braking, that indicates it is locking up, which could cause skidding and loss of steering control. ABS is supposed to intervene by rapidly "pumping" the brakes at the wheel that is locking up, allowing it to spin so that the driver retains braking and steering control.