K&N parts matching AC Delco A3121C air filter

The AC Delco A3121C 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
Laurent Desvigne, Miserey Salines, France
Hello! I received my K&N air filter in a reasonable time and I am anxious to install it.
Jesse, Calgary, Alberta
I was impressed by the increase in throttle response, especially at the low end. You can definitely tell how much better the engine is breathing by how much faster you climb through the first 3500-4000 rpm. The gains are modest still, but worth the money, especially if you just dont have the available funds to buy a full cold air setup.
Kevin, Scottish Highlands
When I bought my Mazda 5 Sport back in February 2018,I decided to do a little service myself. One of the things I decided to change was the OEM panel filter for something that allowed the engine to breath a bit better. The panel filter is much thinner than the standard one,and is really easy to fit yourself.It also gives a nice subtle growl when on full throttle higher up the rev range.The filter also comes with a little K&N sticker for your car,and a handy warning sticker to pop onto your OEM airbox,or under the bonnet,to remind your mechanic that it is a long life filter,and to not be thrown away. Due to that, I'll never need to buy another filter panel for my car again,so its already worth the money paid.
33-2293 K&N 33-2293 Replacement Air Filter
List Price: $75.79
Your Price: $48.99