HACKED...By Owner?? ('98 GMC Sonoma: EGR Fault P0404-P0405)

Owner of this 1998 GMC Sonoma drove from over 4 Hours away because his truck cannot pass the State Emissions Inspection. Check Engine Light is ON setting EGR Valve Position Codes P0404 and P0405. After replacing the EGR Valve with a cheap aftermarket unit, the owner tried to "bypass some wires"...and created a giant MESS under the hood! Now it's up to us to diagnose the actual issue, and restore the truck to factory spec so it can pass the Emissions Test. Let's follow the DATA and efficiently track down the problem. I have a feeling we won't need any extra parts :) TOPDON Phoenix Plus: https://www.amazon.com/dp/B091BQNR3S?... AstroAI Digital DC AMP Clamp Meter: https://www.amazon.com/dp/B08MTCMWLB?... ATD Tools 5513 Heavy-Duty TEST LIGHT: https://www.amazon.com/dp/B000M5ZWBA?... UY CHAN TS101 SOLDERING IRON: https://www.amazon.com/dp/B01MD12DYT?... Enjoy! Ivan