this is your P0304 code

if you have not gotten this plug out yet, use compressed air to blow the crap out from around the spark plug.

 

What kind /brand of plugs and replacement COPs did you use?
Motorcraft plugs work the best in the Triton motors.

 

You've got lean codes on both sides.. VACUUM leak. Again check the PCV system especially the elbow at the back of the throttle body. 304 missfire could be from the Vacuum leak-worry about fixing that FIRST. Check the intake system in general for vacuum leaks you obviously have a major one..

 

if you used anything other than motorcraft or autolite id change them cause anything else doesnt last long in the triton engines.

 

The pcv valve is still in its seat and hasnt popped out. I had replaced 2 02 sensors before I knew about my cat and misfire problem. I have bought all 4 but havent put them on yet. I was just outside trying to find a vacuum leak but I haven't discovered it yet im at a loss I will change plug maybe tomorrow . I used bosch plugs when I changed all of them a few weeks ago.

 

Don't use Autolites in the 99. The 103's and 4's are the wrong heat range and will misfire. Yea, -Motocrafts instead.

 

These are the worst plugs possible to put in these engines. Eventually, they will overheat in the chamber and fall apart in the cylinder. If you don't know, ask here or follow your manual.

 

And what COPs did you use?

 

Thanks, I had used bosch before at 115k miles and i got 225k miles now so figured they were good so put them back but I guess I was wrong. I have been searching for vacuum leak all day and decided its going to dealer to get diagnosed and fixed my other half said I need to go get a new f-250 and be done with it very tempting but I love my f-150 to hunt with.

 

Hey, if you've got the ok already,just go pick out a new F-250 diesel with the new 6.7 in it.
My father bought a new one and that thing is sweet and will set you back in the seat on take offs.
I'm sure it would make a nice hunting truck.

 

LOL... If I go that route that truck will not be a hunting truck for atleast 5 years lol... I am taking truck to dealer tomorrow to drop it off and monday plan on test riding one lol... I may look at a new 150 but if there like the older ones and its a M.F to change plugs like my 99 I won't buy one..

 

yea bosch is the worst plug to use in a triton.

 

changing the plugs on a 99 isnt that bad. Shoot its nearly just as hard to do the plugs in my 71 mach i. Try doing an E-series van with a 5.4. Those are hard.

 

Man I hate working on those vans. However, I have changed an engine in one. That was fun.... Lifting the van off the motor,- without a lift. I survived.

 

Vans would really suck.... I have a chevy astro and I do not fool with anything on the engine I feel for you guys on the vans. oh those bosch worked well for me that time... I will see what they do this time. The cops were some i bought off ebay that someone had recommend to get them they had lifetime guarantee.

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT