I can tell ya that the state patrol here is becoming more and more educated on how to spot a deleted truck but unless you are rolling coal or have stupidly loud exhaust, they tend to leave you alone. Emissions test is every 2 years for the Denver metro area diesels over a certain age (5 years I think?) at the place I go that does the E-Test (independent repair facility, certified by the state to do the dyno e testing) they know their stuff. They hook up to the OBD system and they do a very very through visual inspection too. Heard talk about how they failed a truck that had an EGR delete/bypass and another guy who gutted out his cat but left the thing on there in hopes of passing the inspection from a visual standpoint.For those of you who live in "vehicle inspection" areas, what can you tell us about "deleted" vehicles.