'06 3500 5.9L Megacab 295k miles
- no aftermarket mods other than cold air intake.
- prior owner had a programmer but nothing on it currently (has EGT port still).
- strong engine and has been a great runner.

I did a short run to the dump, and on the return trip, I could smell diesel.

When stopping had smoke came out from the hood.

Getting back to the house, I had a trail of diesel along the road into my driveway.

I am looking for input from those who know the fuel system better and are interested in upgrading it to make it more solid and stable.

I tried to assess where the leak was coming from and sprayed from behind the fuel filter area somewhere towards the firewall.

The engine ran fine while driving it back to the house.

This makes me think it must be on the return fuel line or a crack in the filter; however, this is a significant leak.

Fuel soaked the entire side of that engine bay.

I threw code P0148 about 5 minutes after smelling diesel fuel while driving.

It got too dark out to see much.

I will be looking for cracks or return line feed connector breakage tomorrow.

Sidenotes:
The truck has 295k miles on it with a stock fuel filter and lifts pump (far as I can tell...never been replaced).

I have had an issue with the truck over the last 1-1.5 years when climbing a long hill with a long decline.

After hillcrest and decline for a minute, the limp mode indicator (dash spring looking light) will throw the limp mode indicator, and truck response is slightly less with performance but seems OK.

The only way to correct this is to reset error codes.

In searching the forum, I found some discussions about fuel issues I had with power decrease and the spring-looking dash light.

That made me think it's time to upgrade to an Airdog or FASS fuel filter pump system. Also might drop the fuel tank and look at the pump and filter to see if there's a blockage.