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
Alex Karros, Illinois
Had K&N air filters in previously owned cars. Lived up to my expectations.
Rony, Illinois
Filter is a great product. My vehicle runs smoother and has new life to it.
Lucas Frommelt, Naperville, Illinois
Going into this product, I wasn't expecting a lot. But WOW! What a change. Who knew an air filter could provide such a change? I just put it into my 3.5L V6 2005 Nissan Altima, and I've noticed an increase in acceleration already. I have nothing on MPG yet, because I have just installed it. The engine has also developed this new sporty whine to it at around 4K+ RPMs. Loving this new air filter!
33-2031-2 K&N 33-2031-2 Replacement Air Filter
List Price: $77.99
Your Price: $50.99