I recently purchased an 06 f150 fx4 5.4L with 60K miles. Just recently my check engine light came on and i've noticed a slight rough idle in park. I took it to autozone and the code read P0422 evap emission leak. Bought a new fuel cap but didn't help any suggestions... EGR valve? Any help would be appreciated thanks.

 

sounds like a vaccuum leak... could be egr... someone more knowledgeble will stop by

 

Not an expert either. All I can suggest is that you check the evaporator line going from the fuel tank along the frame rail to a canister in the engine compartment. Look for cracked or disconnected rubber hoses.