Hey everyone, recently I’ve noticed my 2013 Focus feeling a bit sluggish and the engine sounds kind of muffled. I checked the air filter, which I last replaced in December 2023. Do you think I should go ahead and change it again, or is it too soon?
I’d just change it. It’s like $20.
Adley said:
I’d just change it. It’s like $20.
Yeah, it’s not about the cost, but I was wondering if it’s really necessary yet.
I change mine every 15-20k miles. Check between the folds of the filter to see how dirty it is.
Addison said:
I change mine every 15-20k miles. Check between the folds of the filter to see how dirty it is.
Or just spend the $20 and save the hassle. 
Addison said:
I change mine every 15-20k miles. Check between the folds of the filter to see how dirty it is.
Where exactly do I check?
Addison said:
I change mine every 15-20k miles. Check between the folds of the filter to see how dirty it is.
Where exactly do I check?
In between the pleats of the filter paper. That’s where dirt collects.
For the price, it’s worth replacing. But if you’re in a pinch, you can use compressed air to clean it out for now. $20 is still worth the peace of mind. Good luck! 
Here’s something most people don’t realize: filters actually work better towards the end of their life. As they get dirtier, they catch smaller particles that a clean filter might let through. I’d say leave it until your next oil change unless it looks really bad.
@Brooke
I had a 2005 Focus and left the air filter untouched for 100k miles. Still ran great when I sold it!
You could replace it because it’s cheap, but it won’t hurt to leave it a bit longer. Just check the pleats for heavy dirt buildup. Common sense should guide you here.
Looks like it’s still in good shape to me.
It looks fine to me too. Definitely not the source of your car’s issues.
You might want to check if the PCM (engine computer) needs a software update. If you can find a Ford specialist garage, it’s usually cheaper than a dealership. Could solve your problem.
You could just rinse it with a hose and let it dry in the sun. Works fine if you’re not ready to replace it yet.