"Accidentally" bought an 05 F150 Lariate at auction. 5.4l with 172k. Pretty clean and ran great. No repair history. Put some Berryman's infector clean in and filled tank. After 80 mi. CEL comes on P0430. I've changed oil 5-30 synth blend, sparkplugs Motorcraft, air filter, PVC valve, cleaned throttle body, ckd for vacumm/exhaust leaks, new coolant, swapped sides downstream O2 sensors. Reset still P0430. Runs great all condutions. 11.6 mpg. I'm going to pull the bank 2 plugs and injectors. Any suggestions, don't want to replace cat unless neccessary. Thanks

 

Looks like you need a new cat

 

What repairs can fix the P0430 code?

Replacing the catalytic converter
Diagnosing and repairing the engine misfire
Replacing the fuel injector
Repairing any mechanical damages in the engine
Replacing the oxygen sensor
Repairing or replacing the exhaust replaced
Additional comments for consideration regarding the P0430 code

Without the proper tools the P0430 can be difficult or downright impossible to diagnose properly. Many different systems and components can cause the P0430 code. One tool needed is an advanced level scan tool, this allows technicians to view misfires, oxygen sensor readings, and live data. All of this aids in accurate diagnosis and avoids costly repairs that are not needed.

Sounds like you need temperature /pressure check of cats . Watch out for injector flooding failure, it can cause a lot of damage .

 

I would proactively change injectors /plugs on that side . New boots and springs . Thats a lot of miles if all orig.

 

And we don't have a serviceable PCV on the 5.4 3V, recommended oil weight is 5W-20 and did you replace boots and springs with new plugs..

 

"Accidentlly", what does that mean? You shouted a number you thought was way too low - and nobody else said anything?


** JUST KIDDING YOU a little !! **.


You've got a bunch of smart guys giving you good advice here. You'll probably wind up with a good truck, and hopefully at a great price.


But, at that mileage, if nothing has ever been done to it, let me start preparing you. You could be facing timing chain / phaser issues before too very long. With all the cheap code readers out there, someone may have just reset the CEL (possibly some pertaining to phasers) and ran it across the auction block.


Good Luck. BTW - Welcome to the forum.

 

It has been so frustrating ,especially since the truck is running great.
It was being sold on-line, I had seen it briefly during preview but not closely. Woke up with 15 min. left, did a quick value ck (for wrong numbers!), but and won. Still should be able to sell it for a nice profit of I decide to and can get the CEL to go off. I suspect the seller (Not Auctioneer) might have snuck it through smog.
I just read something about plugs being ejected. After I had driven a couple of weels on the new plugs, I pulled bank 2. I was going to post pictures because plugs 5&6 looked like the anti sieze was subjected to excess heat maybe blow-by! could this be causing my code? I'll post pics, they are on my computer so when I get on it, I'll put them up.
Thanks again, this forum is fantastic!

 

I can tell you, you hit the jackpot. A all four members who responded to your post first are among the best.


CATS are difficult to diagnose beyond that which the PCM does as a matter of federal mandated OBDII continuous diagnosis, which produced your P0430 DTC. That's regrettable because they are not cheap.


If you have access to a scanner capable of graphing voltage outputs from the O2 Sensors - upstream and downstream, (I use Torque Pro app on my phone). In this way you can VISUALLY see if the downstream signal levels out at a reasonable voltage of say .6 to .75 volts or so after engine reaches full operating temperature. If the downstream simply 'tracks' or follows the normal upstream waveform signal - the CAT is DEAD.






Upstream and Downstream O2 Sensors for Bank 1 and Bank 2




------
Other than that, you are pretty much left with the expense of 'throwing parts' at the problem. Plugs - Boots - Boot springs - maybe COPS (which I discourage) - or O2 sensors themselves. And you might still wind up with the same result.


Good Luck

 

Yes, like a melted cat.


So lets take a technical approach. So far you have addressed basic maintenance items. I did not see new boots and springs on that list. They are cheap, around $35 for a set of 8. I have used BWD and had no problems. After that, if you are sure injectors are good, inspect the cats visually and then take a temp reading after a long drive cycle. As always a very hot cat suggest its clogged.

 

As I said, after driving for a couple of weeks on the new plugs, I decided to pull them too see what they looked like. I only pulled 1&2 and 5&6. 5&6 as you can see in the pics, are discolored up into the threads. It looks to me like they are being exposed to exhaust. Could this cause my 0340 code?
I haven't changed out the springs, boots or COPs yet. Pulling the injectors today.
Thanks again.



1&2



5&6 Back



5&6 Front



5&6 Side