Honda K20Z3 Oil Cooler Hoses 19422-RRB-A01/19423-RRB-A01

Genuine Honda K20Z3 Oil Cooler Hoses (19422-RRB-A01 & 19423-RRB-A01) - 2006-2011 Civic Si

These are the hoses nobody thinks about until one of them starts weeping oil down the side of the block. On the K20Z3, the oil cooler hoses carry oil to and from the cooler, and they're EPDM rubber, which means they live a hard life. Constant heat cycling, engine bay temperatures, and years of flexing eventually take their toll, and a tired hose either seeps, cracks, or lets go at the worst possible time. These are the genuine Honda replacements, and they're sold individually, so you can replace just the one that's leaking without paying for both.

Which Hose Do You Need?

This is the important part, since you're buying them separately, and telling them apart is easy once you know what you're looking at. The two hoses are shaped differently, so identify the one that's leaking and order that part number.

The inlet hose (19422-RRB-A01) is the U-shaped one. It has the tighter bend that curves back on itself, so if the leaker is the short, sharply curved hose, that's the inlet.

The outlet hose (19423-RRB-A01) is the longer, straighter one. It runs with a much gentler shape, so if you're looking at the long hose without the tight U bend, that's the outlet.

Trace the wet hose back to figure out which one has gone, match it to the shape, and order that part number. If both are old and seeping, or you'd just rather do it all at once on a car this age, grab both and be done with it.

Why Genuine Honda Is The Move Here

This is an oil line, so this isn't the place to gamble on a cheap universal hose. These are the exact EPDM rubber hoses Honda spec'd for the K20Z3, shaped to route correctly and sized to seal at the factory connections without fighting them. OEM rubber holds up to the heat and the vacuum conditions in the engine bay the way a generic hose won't, and it fits right the first time so you're not wrestling it into place or worrying about a connection that doesn't seat properly. On something carrying your engine's oil, correct and reliable beats cheap every time.

Do Both While You're In There?

Worth thinking about. If one hose has aged out on a 15-plus-year-old Si, the other one usually isn't far behind. Replacing just the leaker is the cheaper fix and totally reasonable, but if you're already in there and the second hose is original and tired, doing both now saves you a repeat trip under the car in a few months. Your call based on what shape the other hose is in.

Fitment

These fit the K20Z3 engine found in the 2006-2011 Honda Civic Si, both the coupe and the sedan. If you're running a K20Z3, whether it's still in an Si or it's gone into a swap, these are the correct oil cooler hoses for that engine.

Who This Is For

This is for the Si owner chasing down an oil leak, doing preventive maintenance on a high-mileage car, or freshening up an engine during a build or a swap. Old rubber is old rubber, and oil cooler hoses are one of those wear items worth replacing before they fail rather than after. Figure out which one you need, or grab both, and stop worrying about that line.

Fits: Honda K20Z3, 2006-2011 Honda Civic Si (coupe and sedan), plus K20Z3 swaps. Sold individually: inlet hose (19422-RRB-A01, U-shaped) and outlet hose (19423-RRB-A01, longer and straighter). Material: genuine Honda EPDM rubber. Type: OEM replacement oil cooler hoses.