Ive done some searching and everything i find says the cat has failed. the print out i got from autozone states:

Probable cause:
Cat converter defective(failure possibly due to #2, 3, or 4)
Engine Misfire or running condition
Large Vacuum Leak
Engine oil leakage into exhaust-valve guide seals, piston rings

After searching it looks like the best place to start is replacing the cat. I bought the truck used. Its a 06 5.4 fx4 with about 104000 miles. stock exhaust. i am going to have true duals put on with bullets and a xpipe. if i take this to an exhaust shop and ask them to look for an exhaust leak near the cats or a defective cat would they be able to tell me? Also if the print out says 2,3, or 4, does that mean my truck has the 4 cat system. what determines the 2 cat or 4 cat system?

 

P0430 is Cat System Efficiency Below Threshold (Bank 2). You've probably got a misfire on one of the bank 2 cylinders (5 through 8). Misfire causes the cat to get soaked in unburnt fuel and the cat fails. Find the upstream problem (COP, Plug, injector or combination of all three) before changing the cat or you'll just go through another cat in a couple hundred miles.

 

ok. i planned on doing the plugs but i was waiting for xmas to come cause i asked for the tool for xmas. what is the COP and whats the chances of the injectors getting stuck open or going bad with just 104000 miles

 

COP= coil on plug.

 

How does it run?

An exhaust shop can use an infrared probe to see if the cat is starting to plug up.

 

runs like a champ. no stuttering or bucking. still plenty of power and sounds fine. only thing that has gone bad is the gas mileage but that's normal for a vehicle with an engine light on.

if the COP is coil-on-plug should i just get new plug wires as well when i do the plugs?

side note: does autozone or advance loan out the special tool for broken plugs or is it a ford specific tool?

 

If it has cops it doesn't have plug wires, there is no need for wires b/c the coil is right on top of the spark plug. Being that it is an 06 5.4 it has cops.

As for the Leslie tool, probably not.

Sounds like you need to get at least a Haynes manuel before you go too much further and do some reading.

 

Probably not an injector stuck in the open position. If it was you probably would have hydro-locked your engine by now. At 104K miles I'm thinking either some bad plugs, bad COP or a bad sensor. If its running fine and you don't have any accompanying misfire codes (P030x, where x=the offending cylinders(s)) it could just be a bad sensor.

 

never heard of COP. all my previous vehicles had plug wires. im gonna find out about the tool at the autozone and advanced to see if they loan it and go from there. then go from there. is there a way to test the sensor other then swapping it to a different plug and seeing if it throws that code? and lastly, just curious but when you install headers and high flow cats on these trucks, what do you guys do about the CELs? does anyone make a MIL eliminator for the sensors or not?

edit: anyone on here want to lend me their broke plug tool for the weekend and ill send it back to them. ill even send you a deposit so you feel better lending it out. i may just try and do the plugs saturday and so its done. is there any way to test the COP to see if they failed?

 

2 ways - by substitution or by a load test at the dealer. The DG511 cops on the 3V seldom fail, but you can buy a whole set on Ebay for around $125.

 

ok. i think what im gonna do is first swap the plugs out and see if that fixes it. if it already threw that code does that mean the cat is junk and needs to be replaced as well or its just starting to clog?

anyone want to lend me their plug puller for this weekend? i can send a deposit to insure ill return it

 

I think once you get the code its no longer able to do its job. You also won't pass inpsection with that code.

 

It's low efficiency - which may or may not be symptomatic of a clog. You have to go get the infrared test to see if it's starting to clog. Did you read my previous post?

 

yes i read that part. does this sound about right then to tackle this? get the test done to see if its starting to clog.

1.-if its not: its probably a bad sensor because there is no unburnt fuel clogging the cat

2.-if it is: then there is a misfire somewhere causing unburnt fuel to clog the cat

solution for 1. replace the sensor and go from there

solution for 2. replace plugs, and the cat?

 

I knew the code would prevent me from passing my inspection. thats why i need to have this stuff repaired immediately because i am due for an inspection