Duramax LB7 2001 DTC P0093 Large fuel leak detected
The 2001 Duramax LB7 often suffers from various forms of limp mode, phantom limp mode etc. Limp mode is when you have a reduction in power with a check engine light and a diagnostic code is set. Phantom limp mode is the same reduction of power, but with no light and no DTC being set. Yes this can happen, primarily with the 2001 LB7 . Chances are if you’ve spent any amount of time researching this issue you’ll come across numerous mentions of people using my tuning to fix this issue. It is usually a P0093 and usually only under load. Everything fuel system checks out yet the code keeps popping up. Clear the code and the truck runs fine. This is an issue unique to the 2001 model year and exists in the Factory ECM programming. There are several bugs be it P0093, P0234 etc. This is all something that has been addressed in my Kennedy Custom ECM programming for Duramax LB7
Now I cannot tell you that you do not have a supply side restriction, a bad CP3, worn out injectors or just plain leaking system. That is for you to diagnose, but I’ll say this. I have had people come to me after spending countless hours and as much as $9000 chasing this bug changing every part in the system only to come up short on the fix. In every case to date, the ECM programming fixed the issue. In some rare cases the injectors themselves have been bad, but I have never heard of parts replacement fixing the P0093.
As with any diesel protect your investment. For more information read this Tech Tip on Duramax Injector failures. The closing remarks outline how to best accomplish a long happy fuel system life.