Clogged engine air filters can reduce engine power, decrease throttle response, weaken acceleration, and increase engine wear. And in very old engines, they can also cause poor gas mileage. If you’re worried about your filter, keep an eye out for:

An engine air filter that looks dirty

Problems accelerating

Engine idling difficulty

An engine that sounds like it has trouble sucking in air

Black, sooty smoke leaving the exhaust

Illuminated check engine light

You can also visually inspect your engine air filter. The filter box is typically located under your hood (check your owner’s manual for the exact location) and can usually be opened by releasing the latches or removing the screws. A clean filter is generally white, off-white, yellow, or red, and it may become darker as it collects more dirt. If you live in a dusty or sandy area, you may also need to replace your filter more often.

Note: When inspecting your engine air filter, look for an accumulation of debris. This build-up can overwhelm the filter. In which case, to minimize any chance of debris falling in, avoid removing the filter from the housing.