3126 high intake temp derate

[tree98]

Cat 3126 I think it's a 2002. Its in derate with a high intake temperature. This truck also has an intermittent code for injection actuation pressure signal erratic. Another thing worth mentioning is that the owner of this truck couldn't get the cover off his air filter housing to change his air filter for about 2 years, not sure how many miles he drove it like that, I'm guessing 20K-30K. He changed the housing and installed a new filter at my shop 2 days ago. I've never ever seen a filter this bad. I don't know if all 3 of these things are related???