Welcome! Sounds to me like you hve an intake problem but need a lot more info. How many miles are on it now and how many since you bought it? What’s your typical type of driving?
P04db was a code I got after I tuned transmission. 20 miles round trip is borderline what these trucks enjoy. They do much better on the highway. But I would venture to say your egr hs failed and ruined the intake.
P04db was a code I got after I tuned transmission. 20 miles round trip is borderline what these trucks enjoy. They do much better on the highway. But I would venture to say your egr hs failed and ruined the intake.
I wouldn’t be surprised to find that egr has failed. Also, some of the egr work if they failed was replaced with original style if the new style wasn’t available