On my 2015 Superduty Diesel, I am running into an issue with registration (due in 2 days) because I cannot get it emissions ready to take the emissions test. A week ago the dealer was repairing a check engine light and erased the codes, I have since gone 175 miles and had 10 engine warm up events but on my scanners emissions readiness function it still shows HTR as not ready, everything else has become ready. I think HTR is heated O2 sensor heater, but does a diesel even have that, I don't know, I'm not well versed in diesels. Why would that take so long unless it's bad?