This is a 2008 6.7 that has had a dpf delete and the guy has done his own tuning and ask me to help him with an issue he is having and I cannot see what is causing it so I told him I would post it here and see if you guys could help.
EGR still intact and EGR tuning still as stock but getting a random P0489 code. I think his valve is sticky occasionally and setting the code. Does this sound likely or probable? That is the only code he is getting.