So I’ve got a 2018 6.7 tuned and delete with full exhaust and EGR blocked off. Before I did the delete it came up with a p0402 code and had very low power after. Did the delete, blocked off egr and unplugged all required sensor/stuff, started it up and it was very weak to rev up in park in drive or reverse it had no throttle response. Changed the MAP sensor with no change, checked air filter and it was good checked intake for any leaks/blockages, found none. Checked low pressure fuel had 58psi at idle cold. Rail pressure at about 4500psi, VGT at 70-80% and boost pressure/MAP reading at 13.5-14psi. The odd thing is that the Engine load % is at about 60% at idle in park and jumps to 70-80 in gear foot on the brake. When the ECT reaches 158F the engine load is at about 30-40% at idle in park and when you put it in gear and hold the brake for about 10 seconds the engine load jumps up to about 75% then drops to 12%, put it back in park and it’s around 5-6% and drives like normal. Until you shut it off and turn it back on the engine load is high again and won’t drive right until you hold the brake in gear for about 10 seconds then normal again.

Anybody got any ideas on what could be wrong? I’m at a loss

 

Did you troubleshoot the p0402 code? More than likely you have a bad sensor and truck is still in limp mode.