Bosch DEF Dosing Valve Unit For Mack – New, 22391563 / 21575532 / 21332704 / 21243945

If you've got a Mack truck with a faulty DEF system, this Bosch DEF dosing valve might be what you need.

It's brand new, part number 22391565 (also crosses to 22391563, 21575532, 21332704, 21243945).

It's the unit that injects diesel exhaust fluid into the exhaust stream to reduce emissions.

Made by Bosch, so you know it's quality.

If your truck is throwing DEF-related codes or not passing emissions, this valve could solve it.

Direct replacement, ready to install.