P0087 Chevrolet -lbz1 duramax code only occurs pulling a grade with a large trailer

Question

I get the code only after 200 miles plus only while pulling my 12,000 lb trailer, I drove 350 miles one way and the code only came on once at about 300 miles and once on the way home at about 300 miles. I'm thinking it's something hard to trouble shoot cause it doesn't happen often enough

Answer 1

The rubber section of the line could become kinked or collapse. Fuel lines that kink or collapse may induce a fuel system restriction and it needs to be repaired. there is a service bulletin 

http://silveradofuellines.blogspot.com/2012/05/tsb-bulletin-silverado-fuel-lines.html

also a DIY (do it yourself) to help you replace the line

http://www.dieselplace.com/forum/76-gm-trucks/64-maintenance-fluids/430062-collapsed-kinked-fuel-line-repair.html