K&N parts matching Warner WAF3974 air filter

The Warner WAF3974 air filter cross references with the K&N air filter parts below. K&N offers compatible air filters for many Warner air filters giving you an alternative.
ProductPart NumberProduct Image 
K&N Replacement Air Filter
  • Designed to Increase Power
  • Million Mile Limited Warranty
Andrew Lund, Miami, Florida
This is my second K&N filter I've purchased. The first was for my wife's car. It was easy to install, and I definitely noticed an increase in pickup. This time I ordered the wrong filter, which brought customer service to bear. Daniel was most understanding and accommodating, shipped me the correct one instantly upon receipt of the UPS tracking number for the return. I haven't driven the car since I installed it, but anticipate the same increased acceleration.
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.
Rob Van Arsdale, Fremont, California
I immediately noticed the increased performance. It was like driving a different car.
33-2293 K&N 33-2293 Replacement Air Filter
List Price: $77.99
Your Price: $49.99
K&N Replacement Air Filter
  • Designed to Increase Power
  • Million Mile Limited Warranty
Jerry Adamo, Lake Forest, California
I've always been very happy with K&N filters for all my vehicles. I ordered this one with free ground shipping. It was delivered in less than 24 hour! FANTASTIC!!! Thank you,.
Philip , USA
Filter for 2010 Miata and 2015 Civic. I haven't had but one drive with the Miata, and I think there is a difference, but with the Civic with a five speed, I'm getting 40 miles per gallon on the highway, and almost that on secondary country roads. I'm still breaking the car in gradually, so I haven't had a chance to really test the performance, but so far, VERY positive results!!
William Smith, Kingsport, Tennessee
Easy to install, fits perfectly. Fair price. Looking forward to years of good service.
33-2335 K&N 33-2335 Replacement Air Filter
List Price: $78.99
Your Price: $50.99
K&N Replacement Air Filter
  • Designed to Increase Power
  • Million Mile Limited Warranty
Clive Williams, Leics, United Kingdom
I have been using K&N filters exclusively for 35 years and would use no other - I still have the my first K&Ns, which are destined for reuse. All our vehicles get a K&N at their first service. The current purchase was for a Mazda 3 I-Stop that appears to be a limited run design. Annoyingly, it is more expensive than the standard larger K&N for this vehicle. Purchase from K&N UK direct was as cheap as anywhere else with a delivery that was swift and trouble free. The replacement and fit were perfect as usual.
Tim Sides, Coedpoeth, United Kingdom
Okay, so first I have to thank the guy who said it fits the i-Stop Mazda 3, because I wasn't sure until I read that. Secondly, the air filter I took off was filthy, had grass in and everything, so basing my experience after that. Can I tell the difference? I think I can, but that might be wishful thinking, the car does feel more responsive, and whereas it had a tendency to stall starting off in cold damp weather, now it seems to be flawless. But I have only done about 100 miles since buying the filter. Am I happy with my purchase? Yes. Would I buy from again? No doubt.
Marek Kozolka, Bratislava, Slovakia
Mazda 2.0l 111kw 2011, the best buy for the car.. Ready for new exhaust system..:)
33-2999 K&N 33-2999 Replacement Air Filter
List Price: $85.99
Your Price: $54.99