2002 Duramax 6.6L Diesel Engine P0234 and P1621 Code Issues After Installing Hypertech Power Programmer

Model: 2002 6.6L Duramax Diesel Fault Code: P0234 Posted: 2006-07-15 13:15

I recently purchased a used Hypertech Power Programmer III for my 2002 Duramax 6.6L diesel truck. After installing it at 50HP, the vehicle triggered two diagnostic trouble codes: P0234 and P1621. I've researched these codes online but found inconsistent explanations. Since I don't have access to a factory service manual, I'm seeking clarification on what these codes mean and whether they are common after installing aftermarket power programmers. Has anyone else experienced similar issues with their 2002 Duramax 6.6L diesel engine?