A friend of mine has a 05 Chevy 2500 gasser and the eng. gose into limp mode and he pulls over for about 5 min. and then truck starts and off he goes again. What could be happing there? Fuel gauge stopped working about the same time as all this started happing.

Well the limp mode should have a error code with it. I would start there and see what is going wrong...

Is it truely limp mode? Codes should tell. I had an import pickup drove me nuts. Sometimes... totally random... it would shut off totally, other times limp along. I never found anything in the fuel filter... but changing the filter would get me going quicker. I retrofitted a glass bowl filter (still never fond anything in the fuel). I found I could reuse the filters & gaskets after they air dryed so I dried them under the cap in the back.Finially, in despiration, I pulled the truck into my shop at the marina where I worked & said there just has to be something wrong in the fuel tank. So I dropped the tank... and in the tank I found 6 or more of the cardboard discs from dry gas containers. They would get sucked against the pickup & cut off the fuel. Opening the filter would relieve the vacume & free the obstruction. Some stupid gas jockey (self serve was rare in those days) had managed to get them into the tank... or was it intentional? I sloshed things around with the slight remaining fuel & eventually caught them all with my mechanic's pick up tool. I drove the truck for 50K & sold it for more than I paid for it.