Engine Air Filter
What it is
The engine air filter cleans the air entering the engine for combustion. It sits in the airbox between the intake and the throttle body.
What it does
It keeps dust and grit out of the engine while letting it breathe. A clogged filter chokes airflow, hurting power and economy; an over-oiled aftermarket filter can also foul the MAF sensor.
Symptoms of failure
- Reduced power and acceleration
- Slightly worse fuel economy
- Visibly dirty or clogged filter element
- A dirty filter contributing to MAF fouling
- Black sooty residue in the intake (very clogged)
Which vehicles need it
Every petrol and diesel engine. Dusty driving conditions clog it faster.
Replacement cost
| DIY (part only) | $10–$35 |
|---|---|
| At a shop (parts + labor) | $40–$90 |
| Replacement interval | Typically every 12,000–30,000 miles (20,000–48,000 km); check at oil changes. |
| DIY difficulty | Easy (DIY) — pop the airbox open and swap the element, usually no tools |
| Recommended brands | Fram, Bosch, Mann-Filter, K&N |
Where to buy the part
We may earn a commission from purchases made through these links, at no extra cost to you.
Frequently asked questions
Does a dirty air filter really affect performance?
A badly clogged filter restricts airflow and can dull throttle response and economy. Modern engines compensate somewhat, but a filthy filter still costs you and should be changed.
Can the air filter affect the MAF sensor?
Yes. A torn filter lets grit reach the MAF, and over-oiled performance filters can coat the sensor element — both can cause MAF codes. Use a clean, correctly fitted filter.