Ok, I've been reading and reading on here and other places and am at a loss. I am running a 2000 Expedition Eddie Bauer 5.4L. I've checked and rechecked several items now and have found nothing. So for I've cleaned and checked the MAF sensor, replaced O2 sensors, replaced PCV valve, checked vaccum lines for leaks (even that blasted elbow behind the TB looks new). I've replaced the fuel filter, and it had a full tune-up to include new plugs, injector cleaning, fluid checks, and the like at 98,000 miles and I am only up to 103,000 miles now. I've taken it to the shop and they have rerun all the same checks and checked every sensor, shot it with some seafoam, did a full vaccum smoke test and still the light comes back after both clearing the codes with the scanner and pulling the batter for 30 min. Any other ideas out there. It runs fine, normal idle ~700 rpm in neutral, accelerates fine, fuel mileage is typical 12 city and 16-17 highway. I'm lost.... Any help would be great.

 

Do you have your brake booster plugged in the bottom port - main vac in the center - evap in the top?

What type of elbow you have. Standing in front of the vehicle looking down at the TB, what side does the main vac line plug into behind the TB ? That will tell me what type you have..

There's a sub-zero PCV system on some models that runs coolant thru the manifold to help heat things up . That will have three legs into one port pass side..If you have this type , main vac will be drivers side middle in elbow..

What's "blasted" mean. - Did you remove the TB and Elbow and clean all ports?

Heres the cold climate model -



The EGR runs to the bottom of the elbow and 90's up - this is the port that usually clogs..

 

Standard version - Vac is on opposite side -