I beleive parts sellers are collectively smoking crack cocaine now there.
The rad cap that is used in a honda civic model 2000 is the same plain old micro cap of 1.1 bar rating that is used in a ton of other japanese cars. This cap is very short and has a plastic vacuum valve with no spring pressure to stick it permanently closed, it seals up when the system gets a bit hot, at which time the pressure valve gives way at 1.1 bar to purge the expanded coolant.
The part number differences are updates or small differences like the original 2000 civic radiator cap having a plastic sleeve on its ears to make it look nice.
You should ask the parts counter to look up “RPT”, its a header called replacement part type which then tells what is the other compatible spare.
Just like they see the RPT for the defunct ewg203 bulbs that are used in older civic dashboard panels. Or the gasket sealant or the coolant specification or the old thermostats and old metal type pcv valves.
If they are not using a paid copy of the parts lookup software then wont see the rpt or all part numbers either.
