Power surge on CM870???

[cowboycurtis]

A little background first. 2007 Peterbilt, 1,000,000 miles. Previous owner deleted EGR but didn’t touch the ECM. I found a lot of help here and now it’s properly tuned to 500HP with help from Momma Burt and others. No check engine light or major problems of any kind right now.

The issue is going up through the gears and putting down a lot of power it will just act like a dog. I grab a gear, put the pedal down and it climbs slowly up to 1750-1900 and that’s it. Sometimes I’ll grab the next gear and the truck is like a rocket. Tons of power and the RPMs will shoot up to 2100. It’s like a a rocket with 150 more HP. Then grab the next gear and it’s doggy again. The engine isn’t missing. Sounds good. Just runs out of power way early. Any ideas what is going on??