OK mechanics..... need help.

[super_dave]

I've pulled thousands of plugs with an impact and never broken a single one. I don't know how they keep breaking for everyone else unless they are really old plugs

Not on a 5.4 you haven't. You would break every one of em with an impact.

[BowSlayer]

I pulled all 8 plugs on my 2006 5.4 with an impact and didn't break 1.

[Eric T.]

Same with my 05 Ranger V6... recently replaced the coil pack. Runs like a champ again.

And was barely a 1 beer job.

Go slower next time.

[47]

A coil pack should give you a misfire code. I'm not getting one. Been there done that.

Mine has had this behavior for a few years, just randomly(while accelerating) would stall/lurch until I backed off. Most days normal, and never saw a CEL until a week before I ordered the pack, had cruise on at 75 and was going up a hill and even then, all I had to do to clear it was remove and reattach a couple plug wires and no more light.

[bwssr]

Go slower next time.

gota have one to open the hood a stare....then 1 while getting the tools, one while doing the work, 1 while listening to it run, 1 to clean tools and one to take a break....

[47]

gota have one to open the hood a stare....then 1 while getting the tools, one while doing the work, 1 while listening to it run, 1 to clean tools and one to take a break....

I'b be asleep on the bed liner by then

[Goldeneagle]

What would cause the EVAP thingy on the firewall to be wet? It's next to the brake booster. This is another reason I'm thinkin fuel pressure.

[dac6933]

Not on a 5.4 you haven't. You would break every one of em with an impact.

This is just not true. I pulled all of mine with an impact and did not break any.

[slomo]

A common problem with thes trucks is a vacuum line breaking it goes from the passenger side valve cover to the back of the intake it should be about 1/2 or 3/4 inside. the main part of it is hard plastic but on each end it has rubber fittings. the fitting on the back side is generally where it tears you should be able to reach back there and feel if it is torn or squishy. I will try to post a pic if you need it i have a few of these engines around here

[Saltgrass Mikerr]

engine performance.

Unmetered air can enter the engine through a vacuum leak, a dirty airflow sensor that is not reading airflow accurately, an EGR valve is not closing and is leaking exhaust into the intake manifold, an EGR valve that is allowing too much flow (because the EGR differential pressure sensor that monitors EGR flow is faulty and is under-reporting EGR flow).
It can also be caused by low fuel.pressure or dirty injectors all this info is online if that helps you.

This is correct !! P0172 is a generic code that is effected by all of the above.