Last month truck went into limp mode out of my state.dealer test drove with fuel pressure gage,said I needed a new fuel rail relief valve,It only throws this code when I'm under load or empty when its hot and humid out.I put in a shim kit on the relief valve and I threw the same code what else could be wrong IE also pulled tank checked pick up sending unit, cleaned out fuel cooler,replaced fuel filter

 

are you runing any programmer or downloader?

 

No programmer running her stock,just took a load too Alabama,still throwing 0087 code.got worse in the heat and grades

 

possibly the FCA on the CP3 would have to check live data going down the road to tell tho.....did they say because of high or low pressure was the reason for the shims?

 

The dealer said I had bypass on the pressure relief valve,so we got the shim kit,onstead of buying a new pressure relief valve.just before I kick the code truck is running strong,blowing more black smoke than usual,alot of soot in exhaust pipe,no cataylac converter,stock muffler,could it be the pressure relief valve sensor has a short?were going to put a load on the truck today and put a hose to a bottle to see if I'm getting bypass on it,and how much bypass should there be under load,with shims in drove truck hard with out a load and got maybe an ounce or two,for a about 15 min.I have a load heading to ontario,Canada thursday ,this truck is my livelyhood,had a 2008 INTL'4300 but the dpf after 300000 miles took out the maxforce 7 motor..junk!!!!NEED HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!