I've had this happen about 5 times now in the past week or so, when backing up the RPM's drop and it will stall and wil show a message saying "low oil pressure". Checked the oil level which is fine. What could cause this? 2005 5.4, 190K miles. (I just changed the plugs and COP's).

 

Not normal .Did you do a hosp clean job . Did you torque them in 25 to 28 foot pounds . Did you use a small amount of dielectric grease on the ends of NEW boots . Did you use denso or oem cops. Oems don't really fail much they just get corroded . What plugs did you use ,they should be sp 546 . 515's were coming out of the box bad . Clean all the connectors and they should all lock on . Its best if you cleaned out spark plug hole tip area with carb cleaner that carbon is rough on plugs going in and out . Failure to change boots is a common fail .
Then you need to see mode six on a reader after you complete some drive cycles .It will tell you if any cyl building raw counts towards misfire cel.
You probably had battery disconnected so it has to do a relearn. While you are at it clean throttle body and maf with the right stuff .
If she doesn't straighten out we will need to look at fuel trims .O2 's and all that . You will also need to check your fpdm on rear axle .That's it i'm out of breath , some say good thing .
Low oil pressure is the result of engine shutting down not the cause .Your oil gauge is an idiot light that reads mid scale for anything over 7 psi . Thanks ford .

 

Low oil pressure is the result of engine shutting down not the cause .Your oil gauge is an idiot light that reads mid scale for anything over 7 psi . Thanks ford .

I would agree... Your low oil pressure happened because the RPM dropped as the motor died.... The pressure was not the CAUSE of the motor dieing.

 

Try cleaning the throttle body. The plate gets a buildup of crud which reduces the airflow at idle.

 

This requires a special cleaner right?

 

No special cleaner required. Brake cleaner works good to dissolve the deposits. Remove the TB and spray the plate down good then scrub it clean with a nylon or brass bristle brush. Hold the plate open and clean the bore as well.

 

Well, either one I have to go buy it anyway....

 

My 2006 5.4l basically went into limp mode when plowing just a few weeks ago. CEL came on; can’t recall the actual codes, but they pointed to the throttle body.

Cleaned the throttle body (with TB spray) and the MAF while I had it apart and it fixed it. The throttle body didn’t look all that bad to me (only 64,000 miles....is mainly just used for personal plowing)