P0171, P0174 after heavy rain

[Joseph Tator]

Not sure if rain was just a coincidence or not but the other day the rain was very heavy, truck sat for 2 days then this morning about midway into my 40 Mile commute the CEL came on. Truck ran fine, no difference in performance. I took it to autozone after work to have those codes pulled up. I also brought it to have fluids topped off. I have done a ton of mechanical work to the truck. I have had all 02’s replaces, fuel system cleaner done, all hoses and belts replaced etc. not sure if this was discussed previously and if so my apologies. Any advice would be greatly appreciated. I’m a veteran single income family of 4 and I’m pretty tired of paying $1,000’s to my mechanic (even though I love and trust him)

 

[Bedrck47]

http://troubleshootmyvehicle.com/ford/4.6L-5.4L/troubleshooting-p0171-and-p0174-page-1

http://troubleshootmyvehicle.com/ford

 

[Big Brian]

http://troubleshootmyvehicle.com/ford/4.6L-5.4L/troubleshooting-p0171-and-p0174-page-1

http://troubleshootmyvehicle.com/ford

those are really good links. Heck the whole site is very imformative

 

[Joseph Tator]

http://troubleshootmyvehicle.com/ford/4.6L-5.4L/troubleshooting-p0171-and-p0174-page-1

http://troubleshootmyvehicle.com/ford

Thank you so much.

 

[Bedrck47]

Your Welcome Hope it helps

 

[toomanytoys]

Lean codes on both banks at the same time show a low fuel pressure issue or a vacuum leak somewhere. Do the good old vacuum test with a can of carb cleaner. Might save you some bucks

 

[Joseph Tator]

Lean codes on both banks at the same time show a low fuel pressure issue or a vacuum leak somewhere. Do the good old vacuum test with a can of carb cleaner. Might save you some bucks

How do you do the vac test?

 

[toomanytoys]

With the engine warm and at idle use a can of carb cleaner and spray small bursts in and around the intake. When the idle jumps a little you found the area where the leak is.

Also check the pcv hose as well as the two vent hoses that are on the drivers side of the intake. Very common spots to develop air leaks. And get in good around the egr valve. That's where I found my leak

 

[rjdelp7]

Possible dirty/bad mass air flow sensor. When you split air filter housing, it is on engine side. Spray it with mass air sensor cleaner only. CRC is best, recommended brand. This sensor heats up and is cooled by incoming air. It sends temp to pcm to adjust air/fuel mixture.