cwcaesar

I recently bought a 2006 F-150 XLT 4x4 145" Scab with 146,000 miles. It makes some noise like the exhaust has been removed, though the tail pipe is still present. I am getting the P0420 and P0430 error codes (catalytic converter efficiency below threshhold) and the Check Engine Light is on.

I am wondering if the Catalytic Converters may have been cut out of this truck. I have yet to crawl under there and look, as I am not 100% sure what to look for. Would these be immediately located behind the headers and look similar to a muffler?

Would having these cut out cause these error codes? Or should I suspect another issue at this point?

If they have been removed, what are my options for exhaust? I love the sound of Magnaflow, should I just put one of their systems in from the headers on back? or should I bite the bullet and put in some long headers from Dynomax?

Either way, I plan to do a Tune up before I invest in the exhaust (i.e., spark plugs, coils, fuel filter, pcv valve). Is there anything else I should do as a semi-routine maintenance item before I go an start upgrading the truck?

Thanks!

Jaytizzle

Your cats might be bad or a bad O2 sensor.


The cats are located right behind the manifold and before the exhaust system starts. If the cats are removed, a cat back exhaust will not take care of the problem. Hence " Catalytic Converter Back ".


As for options on Exhausts, there are actually A LOT of options for you. It really comes down to the style and sound you are looking for...Magnaflow, Gibson, Flowmaster, Banks etc...


JT

cwcaesar

Yeah, I understand that a Cat Back Exhaust won't address a Catalytic Converter problem. I just didn't know if I should throw a good full exhaust on there, or if there is another issue that could be creating a problem for a Catalytic Converter that I should address before spending the dough on the exhaust.

I guess I will crawl under there and see if the Cats have been cut loose.

Thanks!

Magna_Flow

I'd start with the O2 sensor if the cats are still there, as Jaytizzle recommended. The cats generally look, as you said, like mufflers but a bit smaller and located right after the headers. There are a few different styles, but here are a couple to give you a general idea of what to look for:








We actually just posted a two-part tech piece on catalytic converters and why they're actually beneficial to run on modern engines (Part 1 here, Part 2 here). Those posts have more pictures, too, that might be helpful.

We don't actually sell a single system that goes from the headers all the way back, but we separately sell direct-fit Catalytic Converters and cat-back systems for the 2006 F150.

You can find the list of cat-backs here.

The links to our cats can't be direct-linked, unfortunately, because of the design of the system, but if you go to our 49-state Catalytic Converters page here, and search "FORD TRUCK > F-150 Pickup > 2006," you can see what we offer there, too.

That's a lot of information, so don't hesitate to PM me to help parse it.

cwcaesar

Update:
After researching the possible causes of the Catalytic Converter Threshhold faults, I decided to start with a spark plug change. So...down to my local O'Reilly's for plugs. I knew of the issue with the plugs, so I asked them if they had the Lisle tool in stock. They had none for sale, but they did have a loaner available. I put down the $120 deposit for the loaner and I was on my way (plus the Motorcraft plugs). I got home and pulled the air intake off and held my breath as I went to work on the first plug...came loose easily. Got it pulled out and I was glad to see Autolite, letting me know that the plugs had been changed from the original problem plugs. So relieved!!!

Anyway, I got all 8 plugs changed with no issue. Only a few hours work and saved myself about $400 from having the local garage do the work. And, this had the desired result of clearing the Check Engine Light! Woohoo!! Success.

I also decided to do some crawling around under the truck to see what was to be discovered as far as exhaust goes. Well...the catalytic converters are in place. I also noticed that there is a Flowmaster exhaust installed. (no wonder I don't like the sound of this truck) I am not a fan of the extra loud noise. Like I said earlier, I thought that the exhaust had been removed completely. Anyway, that's a problem for a different day.

How can I tell if the Cats are original to the truck or if they have been replaced as well? I couldn't see any markings, but I could have overlooked them. There is a bit of surface rust all the way from the headers to the tail pipe.

I think my next project will be the Coil Packs and the Fuel Filter replacements. Then maybe the Oxygen sensors.

uzikaduzi

not really what you're asking but, if you had a spark plug that was bade enough that it was throwing raw fuel down the exhaust, those cats maybe on their way out now

cwcaesar

Yeah, I have considered that, but I want to be sure the initial issue is fixed before I install new cats and have them ruined too. The plugs didn't look that bad. I will post pics later and get another opinion on the condition of the plugs though.