PRODUCT DETAILS
Honda Civic Engine Air Filter K&N Si (12-15)
Your 2012-2015 Civic Si uses a paper engine air filter in the factory airbox. When that filter is dirty, K&N 33-2473 is the washable Honda Civic engine air filter that drops in the same box on the FG4 coupe and the FB6 sedan.
What It Is and Why It Works
The trade here is paper against oiled cotton, and it is worth being honest about both sides. Honda paper filters fine, and you bin it every service. This is four layers of oiled cotton gauze that you wash and keep for as long as you own the car. K&N rates the media at up to 99 percent overall efficiency and says it only needs cleaning every 75,000 miles under normal highway driving, both per manufacturer. It ships pre-oiled, so it goes straight in the box out of the bag.
What you give up is the oil-free part, and that matters on this car. Over-oil a cotton filter and you can put oil film on a hot-wire sensor, and then you are chasing a driveability problem that the filter caused. Use the right amount, which K&N puts at 0.85 oz for this panel, and keep the oil off the gasket face. If you would rather not think about oil at all, buy a dry filter instead and stop reading here. If you will clean it properly, this is the correct Si 2.4 panel and it is the last one you buy for the car.
Set your expectations on power honestly. A panel filter sitting in a stock airbox does not make horsepower you can feel. The restriction on a K24Z7 Si is the box, the snorkel and the head, not the element inside it. Buy this because you are tired of replacing paper, not because you expect a dyno result. K&N backs stock-replacement High-Flow filters with a No-Hassle Lifetime Limited warranty, limitations apply.
Read the engine before you order, because a 9th-gen Civic is three different cars. This page is the Si K24Z7 2.4 only. A DX, LX, EX, EX-L, or HF is an R18 1.8 and takes a wider panel. The Hybrid is a 1.5 and takes a smaller square one. Same generation, three filters.
Specs
| Manufacturer Part Number | 33-2473 |
| Hybrid Racing SKU | KNN-33-2473 |
| Line | K&N High-Flow panel engine air filter |
| Position | Factory engine airbox, one filter |
| Honda OE cross | 17220-RX0-A00 (K&N lists 17220RX0A00). Same number is also listed as Acura 17220RX0A00. |
| Panel size | 10.188 in x 6.375 in x 1.063 in (259 x 162 x 27 mm) |
| Material | Cotton gauze, oiled, 4 layers, per manufacturer |
| Filtration efficiency | Up to 99 percent, per manufacturer |
| Re-oil amount | 0.85 oz (25 ml), per K&N |
| Service interval | Clean every 75,000 miles under normal highway driving, per K&N |
| Weight | 0.9 lb (0.4 kg), per K&N |
| Contents | 1 engine air filter, pre-oiled. No intake kit, no cleaner, no oil bottle, no cabin filter. |
| Warranty | No-Hassle Lifetime Limited, per K&N. Limitations apply. |
Fitment
| Year | Make | Model | Trim | Engine |
| 2012-2015 | Honda | Civic | Si coupe (FG4) | K24Z7 2.4 |
| 2012-2015 | Honda | Civic | Si sedan (FB6) | K24Z7 2.4 |
| 2013-2015 | Acura | ILX | 2.4, 6-speed | K24Z7 2.4 |
Factory engine airbox, Si 2.4 and ILX 2.4 only, and it is not a cabin filter. The FG4 coupe and FB6 sedan share this panel. K&N live vehicle catalog lists 33-2473 on every 2012, 2013, 2014, and 2015 Civic Si 2.4L page, and on the 2013-2015 ILX 2.4L pages. A 2012-2015 Civic 1.8 (DX, LX, EX, EX-L, HF) takes K&N 33-2468, a wider panel at 9.375 x 7.25 x 1.063 in. A 2012-2015 Civic Hybrid 1.5 takes K&N 33-2348, a smaller panel at 7.375 x 7 x 0.938 in. A 2013-2015 ILX 2.0 takes 33-2468, not this one. A 2017 Civic Si is a 1.5 turbo and takes 33-5044. If you already run a K&N 69-1019TS Typhoon, that kit uses conical RU-4600, not this panel. If you are not sure what you are holding, measure it: 10.188 by 6.375 inches and about an inch thick is this one. Wider and shorter is the 1.8. Nearly square and under 8 inches is the Hybrid.
What to Know Before You Buy
Buy the right chemicals with it. This filter is oiled, so when it comes time to clean it you need K&N cleaner and K&N oil. Dry-filter cleaner is the wrong bottle for this media, so if you have an AEM DryFlow spray on the shelf from another car, leave it there. Wash it, let it dry all the way, oil it lightly, done. The most common way people ruin one of these is soaking it and putting it back in wet.
Confirm the engine before you order, not the badge. If the valve cover says 1.8, or the car is a DX, LX, EX, EX-L, HF, or Hybrid, this is the wrong SKU. If the car already has a K&N 69-1019TS Typhoon on it, that kit came with its own conical filter and this panel does nothing for you. And if you came here looking for the thing that stops the cabin smelling stale, that is the cabin filter behind the glovebox, and it is a separate part.
While the airbox lid is off, spend two minutes on the rest of it. Check that the lid gasket is seated flat and the clips all latch evenly, because a warped lid leaks more air past the filter than any element flows through it. Look at the PCV plumbing that feeds this box too. A soaked elbow puts oil mist upstream of a brand new filter, and then people blame the filter. Snug the intake tube clamp on the way back together. That is the whole job.
2012-2015 Civic Si K24Z7 2.4 coupe and sedan, plus 2013-2015 Acura ILX 2.4. Factory engine airbox only. Does not fit a 2012-2015 Civic 1.8 (K&N 33-2468) or Civic Hybrid 1.5 (K&N 33-2348). Measure the panel: 10.188 x 6.375 x 1.063 in is this one.