Description
The PAI 131878 is an exhaust outlet connection gasket for Cummins ISX15 and X15 engines, replacing Cummins OEM 3684359 and the superseded 3684255. The gasket seals the turbo outlet connection to the exhaust manifold flange and is used on EPA 2013-and-later 15L XPI applications.
Signs You Need a New Exhaust Outlet Gasket
- Ticking or chuffing sound from the turbo outlet under load
- Black soot trail at the exhaust outlet flange
- Exhaust smell entering the cab or engine bay
- Visible carbon track or blow-by at the joint between turbo outlet and manifold
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 131878 |
| Part Type | Exhaust Outlet Connection Gasket |
| Engine Compatibility | Cummins ISX15, X15 |
| OEM Reference | Cummins 3684359 (supersedes 3684255) |
Cross References
This part replaces or is equivalent to the following part numbers:
- Cummins: 3684359, 3684255
Applications
This gasket fits the following engines:
- Cummins ISX15 (EPA 2013, XPI fuel system)
- Cummins X15 (EPA 2017+ Performance and Efficiency Series)
Representative vehicles using these engines:
- Kenworth T660, T680, T800, T880, W900, C500 (2013–present)
- Peterbilt 367, 386, 388, 389, 567, 579, 587 (2013–present)
- Freightliner Cascadia, Coronado, 122SD (2013–present)
- International LT, ProStar (2013–present)
- Volvo VNL, VNR (select 2013–2018 ISX15 builds)
Verify your engine serial number and configuration before ordering to confirm fitment.
