You absolutely should not use it, throw it in the bin.
Run a K&N on a track car if you have to, but not anything you use on the street and definitely not anything you want to look after or use off-road.
A 4wd publication did some testing in Oz a while ago, and tested a genuine Toyota filter, Terrain Tamer, Ryco (I think) and K&N.
If we call Toyota's filtration quality 100, Terrain Tamer was around 98, Ryco was early 90s, K&N was about 60.
Not worth it for what would be a very marginal gain. If you want more power, ensure everything is healthy (ignition, fuel, compression etc) add some headers and a 2.5 inch exhaust and do something with the camshaft. If the head is off anyway, match the ports, clean up the runners etc. Don't feed your engine on dust with a so-called high flow filter.