Sounds like a plugged up cat.

 

What exact plugs did you use?

Definitely a plugged cat. You can probably thank the Seafoam for that.

 

I used the motorcraft platinum, gapped to .56

It was running fine until I went to park it, we cane back out to start it up to get my girlfreind and it started missin like crazy sounded like the pass side exhaust was loaded up and tryin to leak out of a weak spot and cat was glowin red, we also unlpugged sone cylinders abd injectors when it was runnin like this and it didnt really make a difference, im assuming cause there was to much exhaust backed up, anyways ye old f150 is probably gonna go down to the shop to have them look it over and put a scanner on it to make sure nothing else is goin on, on the upside to all of this is when it was runnin fine I didnt hear ping so wr must be getting closer here

 

Welcome to the world of driving with unleaded fuel. That pinging is something that happens over time with unleaded fuel. The valve seats get screwed up. There is two ways to get rid of it the high octane stuff or heads off and clean or replace the seats or valves. That was the nice thing about leaded fuel you didn't have this problem.

 

We'll the shop told me to replace wires to make sure the old ones aren't causing any problems so I'm gonna replace wires and go from there, but I do think the cat is gonna have to be gutted or cut out

 

U have a lean mixture. Problrm is in the intake.

 

K so I changed wires and it's running fine now, the cat was red because of it missin really bad and dumping fuel into the cat and the cat couldn't burn it fast enough, so that's a + but the pinging is indeed still there

So back to the list of thin done

Cleaned maf
Took throttle body off cleaned egr ports
Checked for intake leaks: none
Cleaned iac
And now new plugs and wires plugs gapped to .55 to .56

Soooo..... Yea kinda scratching my head again here

 

Raw unburned fuel is what cooks the cats.

 

Yea I would imagine it can and would, but I didn't run it to long like that, maybe half a mile, seems to be fine now, exhaust sounds the same and it seems to be flowing good, the passenger side cat seems to be the same temp as the driver side, I checked it last night after a long test drive and the cat wasn't glowing or red or anything so I'm assuming it didn't melt the inside of the cat but I've been wrong in the past

 

So any advice on what the next step I should take here?

 

try the high octane gas and add a octane booster. see if that helps. otherwise the pinging isn't going to go away. It is from the unleaded fuel. Look it up.

 

The cats got clogged because it ran like crap for way to long.. pay now or pay later with penaltys. Because of lack of maintenance the cats need to be replaced.

 

Well I cant replace the cats because new ones are to expensive, the only thing I could do to them is cut them off and put a pipe in its place, I dont think the cats are screwed mainly because the only one that was glowing at the time was the pass side one and now its not even gettin hot and it soubds the same as before, makes good power even going up hills seems to run s little better with these new plugs and wires than before

 

So far with the new plugs and wires it seems to be pinging on 91 ocatane now, I've checked for vac leaks again and found nothing, seems like it's just becoming a dead end

 

Are you sure it's pinging?? the reason I say that is if your oil preasure is low your valve trane will make that type of noise amungst other things. Just a thought. The dummy light may not be going off.