Forum Discussion
ScottG
Aug 22, 2014Nomad
The service manager is talking about stuff he knows nothing about.
The DEF never enters the fuel system and doesn't go anywhere near the injectors. It's injected directly into the exhaust stream after the cat converter. (This is why DEF is referred to as an "After treatment").
Bad or old DEF will not "gum up" anything but it will throw a code and can result in limp mode if bad enough.
The DEF never enters the fuel system and doesn't go anywhere near the injectors. It's injected directly into the exhaust stream after the cat converter. (This is why DEF is referred to as an "After treatment").
Bad or old DEF will not "gum up" anything but it will throw a code and can result in limp mode if bad enough.
About Travel Trailer Group
44,059 PostsLatest Activity: Mar 18, 2026