Help With Codes

[dkolewaski]

My truck keeps throwing P0171 & P0174 Engine too lean on banks one and two. What does this mean? Am I gonna blow my engine? I just got it back from the shop they did upper intake and gasket, it was fine for a trip to work and just made it back. Can anyone please help me out?

 

[jah81592]

These are lean codes. I would check to see if you have any manifold vacuum leaks between your maf and heads.

 

[techboj]

from the book it says: Lean codes 02 sensor bank 1 and 2
from experience - its a vacuum leak. Search for intake manifold gasket leak. It's been discussed several times. Sometimes tightening / torquing down the plastic intake helps a little but replacement isn't too difficult or expensive.

I called a local Ford dealer and mine costs less than CAN$3 each or about CAN$25. Mine's a 99 4.0 DOHC

 

[dkolewaski]

I just got the upper intake gasket done at a shop would it need retorquing after some driving? What would you torque it too.

 

[akrada]

Did they do both upper and lower intake gasket or just upper ? The torque for the upper is only 53-62 inch pounds which is just under 5 foot lbs. As for the lower its like twice that. Just did my lower today as i did the upper a while back and no difference as a matter of fact the upper look like they were good when i changed them just looked like who done them didn't put in the little extra work to change the lower set as they looked stock and receded in to the manifold as the new ones seals 100 time better.

 

[dkolewaski]

Turns out it was thermostat temp sensor.. its all good now thanks..