F150Torqued

I believe that your plug situation would produce one of several different misfire codes BEFORE a P0430 (Catalyst Efficiency failure). The catalyst monitor routine ran by the PCM is very extensive. If you have a copy of the Motorcraft OBDII Theory of Operation Manual, it provides some interesting reading on pages 4-7. Basically the PCM counts rich to lean and lean to rich voltage transitions of the front O2 sensors over a period of time - under specified driving conditions, and compares that to the occurrences of similar switches in downstream O2 voltage readings. Above a pre-defined ratio is defined as less than acceptable catalyst efficiency. Bottom line, I think @Summers22 is correct - "Looks like you need a new cat".


As for those spark plugs. -- I'll catch hell for this from other members, but I disagree with the TSB on ANTISEIZE. Your plugs have anti-seize all over them - on the threads - hex nut - completely up on the ceramic. No one can tell about the anode because that 'crap' got 'baked' on and dried out just about like the carbon deposits that it is supposed to help keep from seizing the plugs in place.


I am NO FAN of "anti-seize" - on spark plugs. Ford engineers developed that long spark plug anode 'snout' extending down deep into the head without touching the walls of the hole beyond the threads. It has to do with heat transfer OUT of the Anode. Carbon build up in that cavity (and Anti-seize) are BOTH BAD, providing a heat conductivity path into the head & water jackets and upsets the designed heat range of the plug. I contend THIS contributes to the random misfire problems on the Triton engines. An extensive discussion on this issue can be reviewed here: http://www.f150online.com/forums/v8-...ml#post5161039


I recommend cleaning the carbon (and anti-sieze) out of the cyl head spark plug hole below the threads, and on your plug snouts, reinstalling them and replace them before passing 50k miles. (they won't break if replaced every 50K) Look at the Boots and springs and get all oily residue off everything.


Good Luck

LeeGood

Thanks I see your point. I was so afraid of the plugs getting stuck and breaking! I read a post that said lay it on thick so I did! I pulled no. 5 plug today and it looked much more normal. see pic. I've seen so many posts that suggest that the 0430 code can be caused by a bunch of other things. With the extensive list of codes wondered why they weren't more accurate. At this point I'd be happy to replace the cat of it is the problem. Thanks for your input. I have come to love the truck but it seems that all of its systems are very delicately balanced!

LeeGood

Most of the anti seize seems to have burned off. I use silicone dielectric compound around the end of the boot.

EBC-150

A light coating of nickel antiseize in supposed to go on the barrel of the plug only, keeping it away from the ground strap. The excessive antiseize on the seat and threads may have caused a false torque, causing exhaust blow by up the plugs. To me something doesn't look right with those plugs anyway. They were new a few weeks ago? The electrodes are burnt back like a plug with many more miles.

BadFish523

I agree the anti seize was put on the wrong part of the plugs. Putting anti seize on the threads of the plug can cause a bad torque as stated and also allow the plugs to work loose over time.

techrep

iTrader: (1)

EBC is spot-on.. only the barrel gets anti-seize.. that's what gets stuck but, even then with the new plugs SP-515, I would go very light on the application.

LeeGood

Funny, I have been putting anti-seize on plug threads for 30 years. Don't remember what shop I learned that in but have always thought thats what it was for. It looks like the anti-seize on the barrel burns off pretty quickly, on the threads to for that matter, so I'm kinda inclined to go with the "change them more frequently" line of thought and soak them like I did this time. Well I'm down to a bad CAT or could it be a bad connection to the O2 sensor? I have several intermittent electrical issues that make me a little uneasy about the wiring. A way to test it? Has anyone had luck with CAT cleaners? Maybe the Guaranteed to Pass brand. I feel that as well as the truck is running, if the CAT is below performance level, it cant be by much.
Thanks again for all of your help. I feel like we are getting to the end. (Fingers crossed)

LeeGood

I talked to a tech at a shop that advertised CAT testing. He said that since it was only throwing the 0430 code that it is probably the CAT. I forgot to say that I did check the temp and it is hotter on the downstream side. Tried to meter it with my digital and it was showing fluctuation but not comfortable with my ability to read what it was.

LeeGood

In addition to the 0430 code, I am also getting a pd 0430 code. I know that means pending, but why would I get both? I will load a video of what the reader says.

F150Torqued

If you have your misfire(s) problem settled down, the P0430 code, pending or otherwise, is easy to diagnose if you have access to or have a friend that has an OBDII scanner that can 'graph' voltage outputs from upstream and downstream O2 sensors on the effected Bank. (Don't pay anyone a bunch of money to diagnose it. You can buy everything you need for thirty bucks).


Credits to @nugget68 for his excellent cell phone screen shots BEFORE and AFTER replacing CATS in this series of posts:
https://www.f150forum.com/f4/misfire...2/#post5069166
https://www.f150forum.com/f4/misfire...2/#post5069252
https://www.f150forum.com/f4/misfire...3/#post5076460


The raw fuel that gets dumped into the CATS as a result of lots of misfires can certainly cause them to overheat and melt the platinum honeycomb inside, and result in the catalyst inefficiency code.


Hope not, but unfortunately I would not be surprised.