475 cat cutting out under load

Fuel pressure regulator? You might not be getting the fuel to keep... often they get weak and will work din under no load .. or "meet spec" i had my truck miss under full load and changed this out and havent had issue since... its simple and cheap. . Hope it helps

 

is ir doing it while the engine is cold? does it stop after it warms up, let up warm up good before driving it

 

Sounds like a wiring harness issue to me. Take it for a drive with the computer hooked up or if you don't have access change it. Cheap money well spent. Check the wiring going to the crank and can sensor also. If you don't have a fuel pressure gauge install one. If you are paying for the upkeep install the guages so you have a idea what the motor is doing.

 

My truck is doing the same thing and I installed a fuel pressure gauge to check pressure. It's running 100 lbs. so that can't hardly be the issue. It runs well until I shift on a hill and get back into the throttle then it's like half the injectors start missing and I half to back out of it and roll the throttle on nice and slow. Just overhauled and put on new wiring harness inside and out. It did this also with the old ecm and wiring so that isn't the problem. I did use the old injectors as they only had 160,000 miles on them. I'm not sure how to check the injectors as it only misses when you pull it hard and shift. Can one do a data log with cat et while you pull it?

 

Dieselman mine will do that to but it's because of the tune I'm running and still have the stock turbo. I either pick a gear I can climb the hill in or roll out of the throttle before I shift. Otherwise is will sound like a flooded gas engine trying to clean itself out.