i have a 2002 that is showing codes po171 and po174.in the past i have always found aa problem with the vac hoses or fuel filter.no such luck this time.the only vac hose i was not able to check was the one that comes from the pvc valve and tees off to the back of the blower or manifold.i am not able to fit my hands back there.does anyone have an idea of how to check this or what i need to remove to get more room? thanks

 

Get yourself a mechanics stethescope and put a piece of vac hose on it. Start the truck and follow along the suspected vac line, if it's leaking you will hear it. If you want to know what it will sound like pull another vac hose that you can reach and listen to that, plug it back in and start hunting.

 

Check the vacuum hose from the break booster it’s best to remove it. If you get black dust all over your hand or the hose has tiny cracks then it is bad.
Cost me a blown head to learn that one.

P0171 - Bank 1 to lean
P0174 - Bank 2 to lean

God Bless,

Suavy