I have a 2015 NX200t. It's been about 121000 miles. the "Reduced engine power" warning appeared on the dashboard yesterday. Today, I found the air intake (before the air filter) clogged up with all stuffs (could had been from those chipmunks). I vacuumed all out and cleaned the washable air filter. (Time to do car wash ready for spring and summer). Then the "Reduced engine power" warning disappeared. Problem solved.