Hello - Anyone else have problems with engine power reduced message on the dashboard. I have an ‘08 3500 diesel truck. It use to read clean diesel exhaust filter with that engine power reduced message but not now. I’ve replaced the air cleaner, new oil change, fuel filter change, and new iat 2 - internal air temperature 2 sensor. I took it to the Chevy garage. I spent 100 on diagnostic. They deemed my mass air flow sensor bad on my 2008 Chevy 3500 diesel truck. I got a cheap $99 one from auto zone and same problem - engine power reduced. Now I bought an original replacement acdelco ( hitachi brand ?) with the same problem - engine power reduced message. Please help!