Express Car Care Answer: That’s a fair question we hear from Denver drivers because the harm takes a while to manifest. Let’s take a small step back and talk about what an engine air filter does.
The air around us contains dust, dirt, pollen, spores, etc. Some areas and times of the year have more contaminants in the air. The job of the air filter is to keep that stuff out of your engine. The benefit to drivers is obvious!
Your engine uses a lot of air – 12,000 liters of air for every liter of fuel – so the engine air filter has a huge job to do. When the air filter gets full and can’t hold anymore dirt, all that air still has to get to the engine, so the dirt gets forced through the filter too and heads on down to the engine. The air flows passed the mass air flow (MAF) sensor on its way to the engine. The MAF sensor tell the engine control computer how much air is coming so the computer can send the proper amount of fuel into the engine to maintain the correct air-to-fuel ratio.
When dirty air is flowing passed the filter, dirt starts to build up on the delicate MAF sensor elements causing incorrect air flow readings. The computer then sends the wrong amount of fuel to the engine. This can rob power from the engine, but the most harm comes from fuel that hasn’t been burned passing through the exhaust system and getting caught in the catalytic converter. This leads to your catalytic converter failing.
A primary cause of catalytic converter failure is improper engine management, often triggered by a dirty MAF sensor which was contaminated because the engine air filter had not been replaced as recommended. As a driver, you can buy cases of air filters for what it would cost to replace a catalytic converter. So when it’s time to replace your engine air filter keep in mind the potential long term effects of putting it off. Talk to your friendly and knowledgeable Express Car Care service adviser and let him help.