isx15 with DPF delete

[djwendt]

I am looking to purchase a local truck, 2008 peterbilt 388 with a cummins isx15. Previous owner deleted the DPF (exhaust still runs thru to look like original but no DPF) but did not touch the EGR. EGR is still functional. Any issues that I would need to be aware of? No check engine light, owner state he gets about 5-6mpg running 72, pulling a conestoga. He did clean EGR system a couple years ago, replaced sensors. Also a new longblock was done about year and a half ago.

Thanks.