Hello, and welcome to Just Answer. My name is Robert, I can help you on this concern.
P0404 code does not come up in the Dodge diagnostic charts for Sprinters. Did you scan it with a generic scanner? if so, post the description of the code and I may be able to cross it to the Factory code...
USED A GENERIC SCANNER IT SHOWED P0404 WITH A MESSAGE OF EGR FLOW CKT RNS
ALSO THE WORD PERFORM AT END.
I'm thinking that is too generic of a term to cross it to a factory P code, I'm assuming the code is trying to say egr flow circuit RNS (not sure what RNS means) Performance. so maybe egr flow performance. Unfortunately that is not close enough to any of the factory Sprinter Codes, If you are able to take it to a Dodge dealer, even if they are not a Sprinter dealer and if you can get them to scan the vehicle with their WiTech scanner and write down the codes for you, I can help to steer you in the right direction. they will likely still charge you their normal diagnostic charge, unless you can just get them to do it in the service write up lane they might help you out and just read the codes for you... That would be a good time to take a batch of cookies in to the service department ....lol it really works, technicians will usually help you out on the sly if you take in a bit of food. We always appreciate that!!! lol