2021 3500 Hard to start and Exhaust System requires service message

[JimE63]

My 2021 RAM 3500 Longhorn Limited Edition is suddenly hard to start and after starting the error message came up saying the exhaust system requires service. Any idea what might cause this? The dealership I bought it from can’t even get me in for another 5 days. Is this a regen issue or something more serious?

 

[H3LZSN1P3R]

My 2021 RAM 3500 Longhorn Limited Edition is suddenly hard to start and after starting the error message came up saying the exhaust system requires service. Any idea what might cause this? The dealership I bought it from can’t even get me in for another 5 days. Is this a regen issue or something more serious?

Could be a few things but sounds like a clogged DPF

 

[JimE63]

Would this still be the case without A DPF warning light on the dash? I guess anything is possible in that regard but all I have the the check engine light on and the engine sounds real diesely, if that makes any sense.

 

[Brutal_HO]

Sounds more like a fuel system issue. Injector or even possibly a failed/failing CP4 although they most often go catastrophic and no start.

 

[JimE63]

Sounds more like a fuel system issue. Injector or even possibly a failed/failing CP4 although they most often go catastrophic and no start.

This is where it gets really interesting. This afternoon when I went to move my truck to make it easier for the tow truck, it started right up and the check engine light is now off. It’s also running almost like normal.

 

[Firebird]

Sounds more like a fuel system issue. Injector or even possibly a failed/failing CP4 although they most often go catastrophic and no start.

The OP listed a 2021, so no CP4 for him

 

[Brutal_HO]

The OP listed a 2021, so no CP4 for him

Doh!

That's what working until 0300 every night will do to you.

Sounds like filters or DPF issue.

 

[H3LZSN1P3R]

The OP listed a 2021, so no CP4 for him

I was waiting for someone to comment that lol