K&N parts matching AC Delco ACA21 air filter

The AC Delco ACA21 air filter cross references with the K&N air filter parts below. K&N offers compatible air filters for many AC Delco air filters giving you an alternative.
ProductPart NumberProduct Image 
K&N Replacement Air Filter
  • Designed to Increase Power
  • Million Mile Limited Warranty
Ingrid Gardner, Bronx, New York
I purchased this air filter (33-2031-2) for a 2006 Red Infiniti Coupe. I noticed the change immediately. First I noticed the gas savings, The car sounds completely different. Definitely more horsepower. I love it. I really do. Change your life change your filter it is worth it.
Kandi Uffer, Lake Forest, California
The performance of the vehicle was markedly better after installing the air filer so much that I was truly amazed. The engine can breath a lot better and the gas mileage has improved. I really like the idea of just cleaning the filter instead of replaceing it every so often too. It's really a great product. Thank you so much, I am spreading the word.
Alex Karros, Illinois
Had K&N air filters in previously owned cars. Lived up to my expectations.
33-2031-2 K&N 33-2031-2 Replacement Air Filter
List Price: $77.99
Your Price: $50.99