You only need 2(stock) fully functional cats to pass efficiency testing (PO420, PO430) (1 per side). Our trucks have 4. To get that code, your PCM has to fail efficiency testing 3 times (not just once)to produce that MIL. Most of the time , that is a LEAK unless you completely removed your cats or maybe you just left one of them connected - a faulty one connected. Did you modify anything?

If by chance one is plugged you'll hear the heat shields making all kinds of noises after shut down - The heat shields will be tinging and tanging like a b^tch right after you shut it off.

Trust me - I know these codes. It's usually just a leak in the piping or the larger cat will crack across the bottom under the the heat shield. It could be an O2 bung leaking which is common after a replacement. I'll ask again - did you do anything to the exhaust ? Your TB has absolutely nothing to do with a 420 code. A 430 code - it's possible the EGR pipe is leaking, but not the 420.

You can reboot but that code will eventually return once it fails efficiency 3 times again and it doesn't have to consecutive.

 

heres a hint...the tubes coming off the DPFE that attach to the EGR tube wont look right when properly attached, yes i said that correct. they will cross. longer one goes toward shorter side and shorter hose goes longer. Bad flow is a reslut of incorrect line placement. I made the same mistake. Also clear the codes with a code reader after replacing sensors, waiting on the ECM to clear it for you could take a while..3 drive cycles 0-55 then 55-0 under normal driving. you cant just go out and run the back roads for 1/4 mile times, i tired that code didnt clear, soon as i cleared it with a reader..poof never came back.

 

jbrew, I baught a flowsound system and had it installed about a year ago. From what I understand he didnt touch the cats but I will look at them today.I thought I mentioned that in another thread, sorry if I didnt.
Also, had an alarm system installed and now my doors have to be unlocked or locked from the key or from the inside, the alarm wont do it. Is it possible the alarm system did it or could it be a relay or what? Again, the alarm can not lock or unlock the doors, I have to do it. thanks,

 

So I have cleared the code again and this time it came back after 70 plus miles or so. I went to a muffler shop and they told me they would install a catco system for both sides $300.00 and just that one side for $160.00. If I did high flows it would be more of course and he would use the flowmaster high flows. Is there that much of a difference between the catco and flow masters and is it worth getting the flows? I believe the catco is $85.00 a piece and flow masters are $125.00. Should I just get one side done or both? I just want to pass my inspection! I was also thinking about if I did get the flow masters, get one for now and when I can afford it get the other in a month or so, would that screw things up with my truck?

OK, im not sure if they were magna flows or flowmasters, either way, how do I know what size to order on ebay? They have links to different sizes and I have no clue.
http://cgi.ebay.com/ebaymotors/Ford-...3286.m20.l1116

These are the magnaflows and I have no idea what size pipes and sh^t to get. Im tired of my truck not running properly or always having a service engine soon light on.
http://cgi.ebay.com/ebaymotors/Ford-...3286.m20.l1116
Help!!!!!! I need to order these ASAP

 

2.5 piping if you have a 5four or 4six - I can't remember what you have - You didn't fill your info in yet of course - and it really SUCKS looking it up.

 

Sorry I tried to put it in and I guess it didnt work. But it is a 99 5.4. Why dont you remember mine? I remember yours, its a 98 4.6 right? Ha!

 

It would be a 4six if I cut the legs off - Black bar just above says "UserCP"/Edit Profile/Scroll down to "Additional Information" and fill in a few blanks. Then scroll down to - "save changes" - I just changed mine - look in the top right corner of my post . I just added "LIKE THIS" lol.

 

So back to my problem, WWJD?? No not what would Jesus do but What Would Jbrew Do? Is there that much of a difference to pay the extra cash to get the high flow cats? Should I get both done right away or can I get one done and the other down the road?

 

You forgot the motor size lol - Oh well , you can fix that.

Anyway, If your sure you don't have any leaks and the problem is indeed inside the converter, then yea , I would do them both at the same time.

I would definitely go with the Magnaflows. I'm running those same converters in the link you posted and like them - No codes or engine light with those.

The stock rear cats can split open @ the belly under the the heat shields over time and cause that code - That happened to me on one side (pass. side) BUT , I didn't receive a code when it happened.

If you notice Black carbon on the outside of the heads by the exhaust manifold , there leaking and that can cause that code.

Yea , 5.4L's use 2.50 Piping.

Tell them you want your old cats back . I think they'll give yuh about $100 for all 4 @ a recycle center.

 

OK, im stupid but where can I locate the exhaust manifold on my 99 f-150 5.4 V8??? I think ill just go ahead and order them and get this sh&t out of the way. Im just tired dude and have done everything in my power to fix this truck because I dont want to give it up, I love that bastard! And thanks for the tip about keeping the Cats.

 

Heres a passenger side shot , looking thru the wheel well -



Heres one I snapped the Flange studes on lol - I replaced them.



Here's another with Long Tube Headers instead of manifolds -




Well , that should give you an idea where to look.

 

How do I know what exact model to get? And should I tell them to dump my rear 2 cats and if I do that, do I need to change anything or add anything to not get codes?

 

Here's my numbers - these came from Troyer -







They were like $149 shipped w/f150online discount. - Yea, you can get them cheaper prolly on ebay.

These are all you need - You won't need any of your stock cats - Take those in for recycle and recoup some of the cost. They'll buy your old cats off of you.

 

Thanks J!!! Should I tell them to drop the other 2 or just leave them on? You are awesome! Do you always take pics of everything? I feel I can ask you for a picture of your shocks and a midget giving the finger and somehow you will have that pic ready to go. LOL!

 

does it matter if they are stainless steel? I know there is a price difference