Today I pulled my secondary air pump to replace the rubber studs which had decayed beyond usefulness. While it was out I inspected the unit and the filter. The rivets on some connections had popped, and the filter was crumbling with age. First I took the pump down to my local ACE, and found some 1.5” #4 flat head screws, star washers, and nuts. The screws fit perfectly into the river shafts which I left in place for structural integrity. I went to my local small engine repair shop and purchased a Honda part #17211-889-000 air filter, about $7. This filter is made of the same material as the secondary air pump filter. So my wife made a pattern of the old filter, and cut me a new one from the Honda filter, and I installed it. Then it was time for the charcoal canister filter. I had taken the charcoal canister filter to the small engine shop as well, and they matched it with a lawn mower filter (lol)! I put that in the canister, and covered it with a circle of the remaining pump filter material, snapped the lid back on. Reinstalled everything, and even discovered a small but elusive coolant leak due to a loose heater hose clamp. Tightened that up, ran the engine up to temp, and voila no more leak and no check engine lights. Took the Disco for a 10 mile ride after a restart, and everything is super!
i posted this so anyone with secondary air with a bad filter, and coming apart could fix theirs without buying a new one. The same goes for the charcoal canister! Why buy a new one for $100 when you can fix it for $7? Be sure to check your pump, those rivets are junk!

https://cimg5.ibsrv.net/gimg/landrov...4125271fd.jpeg
Secondary Air Pump repaired with 1.5” #4 flat head screws, star washers, and nuts. Screws fit into rivet sleeves, so no need to remove the sleeves.