hi l have a 07 silverado 4.8l 4x4 with a air aid c.a.I. dynomax ultra flow muffler,bully dog programmer, gas king on the truck with 80,000km a month ago a code came up with out thinking l erased it if l can remember correctly it said Evaporative Emission Control System Purge Control Valve Circuit didn't right it down now a couple of other codes came up this time l wrote them down p0171 and p0174 can this be related to the evap code how can l fix this problem

DTC Descriptors:
DTC P0171 Fuel Trim System Lean Bank 1
DTC P0172 Fuel Trim System Rich Bank 1
DTC P0174 Fuel Trim System Lean Bank 2
DTC P0175 Fuel Trim System Rich Bank 2
These all concern fuel trim, whether it's too rich in exhaust, or too lean in the exhaust. These are frequently misdiagnosed as faulty "O2" sensors but the problem usually is actually somewhere else.

Evap system codes will usually begin: P04XX
You probably had a P0443. A couple different things could be the problem, and unfortunately, they need hands on diagnosis by someone familiar with the system and how it operates.
You don't want to start spraying it with parts till it's diagnosed. That could get expensive quickly!