My Ford F150 2004 4.6ltr (V8) 68,000 miles. Truck really slow getting up to speed. The other day driving into work the truck started losing power vibrating badly.
Went into ford dealership and it took 2 days to find the problem. Ford said it was catalytic converter passenger side. Or they called it Cat convert. That quoted my $2100.00 to replace.
Ok I went to Big Al's mufflers in VA. They said nothing wrong with the catalytic converters. thank goodness for that. They came up with stored codes P0300 Random Misfire Detected and P0351 Ignition Coil A Primary circuit fault in (A) and miss firer with the first 1000 rpms. It never came up with which coil was bad.
About month they pulled the plugs and they were brown I guess meaning its running really hot. Were replaced with autolite ones. Had them replaced along with 3 caps. Cause of codes172 and 174. Sill ran bad.
Now had towed as its undrivable to local garage and now sits in their hands.
Any advice on what it might be?
If they put parts in that don’t fix the issue
Thanks in advance to the experts out there

 

How about proof reading what you wrote. I couldn't get past the first paragraph.

 

I'd take it back to the original dealer and tell them to replace the cats....for free. They have an 8 year or 80,000 mile warranty mandated by yer Guberment.

 

Hard to follow....

Oops, read the numbers wrong.
disregard.

 

random missfire is probably on because of the bad coil, coil A is number 1 cylinder right, first on the passenger side

 

You are pouring raw gas into your cats from missfiring. The trans codes are secondary to the miss condition. Change all plugs and suspect coils and clean the MAF. JMO Any after market components?

 

Harder to understand than differential calculus.

Here are the codes (I think this is what codes you had), what they mean, and probable causes:

P0172: Passenger side bank rich
P0174: Driver side bank lean

Probable causes:

- Excessive fuel pressure
- Leaking or stuck closed fuel injectors
- Leaking fuel pressure regulator
- Low fuel pressure
- Vapor Recovey System problems
- Air leaks after Mass Air Flow sensor (intake gaskets, throttle body)

P0300: Random Misfire

Probable causes:

- Camshaft Position Sensor problems
- Low fuel (less than 1/8 tank)
- Stuck open EGR valve

P0351: Undetermined Ignition Malfunction

Probable causes:

- Open or short in ignition circuitry
- Open coil driver circuit
- Damaged coil(s)
- Damaged PCM

I would start looking at those injectors and coils REAL CLOSELY, and see if there is anything wrong with them. I would also suspect those plugs (I have never had luck with Autolites in modular engines, only Motorcraft for me) could be going bad (even with the short time they are in the engine). Also inspect the MAF and throttle body for any leaks, along with ALL gaskets in the intake system.

As to the catalytic converters, if the engine has run with this miss for any period of time, you may have sent raw fuel into the cats, and they need to be replaced, as they may be partially plugged, causing the slow accelleration.

I think I have covered everything I know could be wrong at this point. I would need to have the vehicle in my sight and touch to further diagnose the problem.

And now,back to calculus.

 

Did you by chance wash the engine lately ?

 

Never washed the truck egine or any rain for about a week.
I just heard from the mech says something the drivers side cat is bad. He said it would be $1500 for just the cat and have to wait a week to get it. and then with labor about $1750.
I may call up Big Als and them I have just gotten the same issue twice. I just get them to order cheap on and install and hope that clears up the issue. I know you can them on line cheap. I wonder if it would ok to run with a non factory one and one other type?
Or should I stay with the engine begin the problem?
thanks all

 

Forgot to add truck has 86,000 miles on it @#$$%%

 

Make sure you are firing perfect on all cyls before you start changing cats. You are showing rich on one bank and lean on the other because the raw gas is giving you bad info to the PCM so its trying to lean out which it is doing to the opposite bank. The mechanic thinks it's the cat but I disagree. I personally don't think you need new cats yet at this point but who knows. You need to get the engine running right first.

 

autolite spark plugs are not the best for a modular motor

 

Ok here's the latest. Had the truck at Midas full service shop. Yeah I know Midas. Having talked with guy he knows his fords well. I explained everything the truck was doing. I memtioned the codes and he knew them well. I purchased 2 cat Magna flows from pep Boys cheap.
He went over thing in the truck and figured out it was the PVC valve and will comfirm tonite with die and smoke. He said that it just crumbling apart. With the air leak the oxygen sensor could not calulate it with the fuel. because it was did not pass by the sensor. Everything is good to go.
I pickup the truck tomorrow after 2 weeks of dealing with delays of other mechs, I hope this is right fix.
My feet are killing from walking some much.
Thanks to everyone for their input and ideals greatly appreciate

 

Bet your glad you didnt go with the 2100 dollar passenger cat.
Wish I could have followed this a little better. PCV elbow is a very common issue. Would have been easy to diagnose.
What happened to the misfires?

 

Well heres more info. I went there on friday and he said the cat was bad/ he said he order a replacement thru Advance Autos and would arrive saturday morning then he would change out. Guess what it never arrived and he never call to tell me. I called about 12 to findout if it was ready no. I talked with the manager cause I was totally pissed. He said he would make calls one Ford had the replacement $1700. I said no way. I said then put on the Magna Flows in replcement. Done on monday picked up waived any Diagnostic charges. Total cost $530. I guess no to back.
I asked for the cats back and he said they had to go to EPA for recyle. Is that right? I thought I could have them then sell to metal place. Does anyone know for sure?
Truck running fine for now