I am new to this forum. I have a 03 duramax with 140k. Just had an airdog and efi live program flashed. Great power but when ever you advance the throttle under load then let off the gas , the engine stumbles, and acts like starving from fuel for 3 to 5 seconds, then slowly returns back to normal idle. it was showing a check engine light and a fuel pressure regulator code. Just put in a new regulator, and still doing the same problem. At any other throttle position it runs fine with good power, minimal smoke , no smoke at idle.
What should i check next.
Thanks
What should i check next.
Thanks