Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Ok here it goes. I have a friend that has come to me. I am that guy that takes stuff that people cant fix and fixes it. Well? I think I have met my match. This truck had the engine replaced due to a bad fuel injector. So right off the top. this thing has new timing component, spark plugs you name it. it is one of those situations with the 5.4, it has zero power. bucks and carries on. Due to what i know about the injector i pulled the exaust down and flipped it up side down and Bank 1 Cat guts came spilling out. Further inspected with a camera and sure enough resonator was clogged as well. By the way this is a farm truck and for off road use only. the resonator was removed and replaced with staight pipe. Now because the engine trouble happend on bank 1 and the Cat and resonator have been removed. I thought that had to be it. put it back together it runs a little better but still has a lot of power loss. Then after a couple drive cycles check engine light comes on with a P0420 Bank 2?????? Im like what the hell how does that even happen? Cat is missing on Bank 1 and doesnt set a code. I pulled the plug for B1S2 and it set a code for the correct bank so nothing is backwards. I plan on doing the same thing to Bank 2 with the Cat and resonator. Keep in mind i havent spent a dime on this yet as i am still collecting data. The only thing i have found in scan data so far is when this bucking occurs the throttle position goes from WOT @ 76 degrees to 30 degrees i mean drops right now. I feel like it is a safe mode strategy rather that a problem. i can mash that thing move it slow full throttle to close and everything works without a hitch in scan data. I do have a scope but have not hooked it yet.
I will be trying to verify the the other cat is bad before i proceed. Any thoughts would be great. this hesitation bucking loss of power is not a misfire just so that is clear. dropped a quick pic of some of the exaust crap
You are correct it is P0430 DTC not P0420. the engine is really good. desired has been equal to. but haven't had it on during the issue ill double check that
The engine was a complete reman 3 year 35,000 mile warranty. it has ran this way since they had the engine put in. Because of the way it runs and knowing the vehicle had a stuck open injector on Bank 1 is why i pulled the exhaust. Bank 1 on a ford 5.4 is on passenger side. the cat and resonator have been removed. the code is for bank 2 and yes its P0430 i accidentally said 420. I did look at the Cat in Bank 1 and it looked clean white and complete. could not see resonator because it crosses over.
yeah is not a timing thing. i do want to take back on the bank 1 resonator I did look at resonator on front side through 02 hole cannot see back due to the cross over but it looked ok
it was replaced before it came to me the case was busted. I have a lot of experience with this hunk of crap. this has me stumped a little. it is ok until it gets warm and WOT. Fuel pressure is good in all stages
He drives the thing everyday all day. Like i said its a farm truck so ot has had the living shit beat out of it. i have made it my goal to fix this thing. I dont throw parts at anything so i am trying to figure it out. what do you think of the TPS dropping out to 30%?
So i cannot explain why the truck had a P0430. The Cat is missing on Bank 1. The bucking and hesitation is fixed. Ran the truck with Mode 6 live and saw a random miss fire on all cylinders but 5 had the most. so i pulled the coils and checked boots and springs checked for debree in the spark plug hole. when i got to number 5 coil i found that the metal bracket that holds the air filter snorkle had rubbed the insulation off of the shared red with green wire. fixed the bare wire put everything back together and P0430 is gone and the truck is running like new.
The TPS signal must have been a safe mode strategy.
If i am being honest it is not what expected to find and it was luck i even saw it.
Funny thing about the CATs and the Data. Both Rear oxygen sensors switch right along with the front sensors. Bank 1 doesnt trip a code and after the coil wire fix the bank 2 code has not repeated. Defies everything i know.
Hopefully that wire thing will help some other cases. that wire set, sits right against that metal plate and im also sure the bolt that mounts that snorkle tube down will hit it if the wire is offset to it.
