hola!
so I just traded my super duty for an 06 f150 5.4, and I'm playing around with money a little, it already has a flowmaster, and I just bought and installed an Edge CS programmer and an intake.... it sounds good and has power with the tuner changing some things around... anywho.. I've been considering deleting the cats, and just keeping the muffler... how ever I noticed that on these trucks, the last sensor is right in the middle of the cat.. not a fan... kinda irritation personally, and the only reason I really see ford doing this is to make people keep the cats in the system.. I'm I don't wanna... and I'm sure if I hollow them out, then I may throw codes, but my tuner can clear them... so if I do this, should I just zip tie the sensor to the side, and well I pipe in the place of the cat, or should i just hollow it out, and keep the sensor in so it looks like i have them in... not worried about emission inspections... and I know that it's not exactly legal... so any of you fella's that feel that you need to make a point to say how much trouble and what not I can get into... I appreciate your concern but save you breath.. or you finger engergy in this case... but any other opinions are welcome!!

06 f150 5.4 3v 4dr lariat 4wd and it's 4x4 not fx4

 

"..............that on these trucks, the last sensor is right in the middle of the cat.. not a fan... kinda irritation personally, and the only reason I really see ford doing this is to make people keep the cats in the system......"

The second sensors detect what's coming out of the cat, and send signals to the ECU to adjust the engine controls to keep the mixture, timing etc where they need to be to run clean and to run right. (not too lean, not too rich)

Some tuners will send the "correct" signal so you can eliminate the second sensor. That way, no CEL, and no adjustment inputs either.

 

yes I do believe that you are right... I guess what i might do is just unplug the sensors and see if it throws a code, I figure if it does though a code then the tuner isn't sending it's own input, and if it doesn't throw a code then the tuner is sending a fake signal.. makes since right? next, if I do do this, do you think that it's going to matter much if I just hollow them out, I only ask because it's going to go from say 2 1/4" to a much bigger diameter, and then back to 2 1/4" with in like 10" of space... so basically the gas willl expand and then immediatly compress just a little as it exits the hollowed cat... hmm... seems like a lot easier to do, but at the same time more work then just cutting it out and welding a piece of pipe in it's place, and I suppose if I did do that then if I didn't like it, or had problems down the road, then I could always weld them back in, and bring it back to stock right? Hmm...

Also on a side note, my buddy has a chevy with the 4.8? I think... anywho, he was getting a rattling in his cat, so we took it out, and sure enough is was all loose, so we punch it out, and welded it back in, until his new high flow ones come this week, anywho, the clanky rattling sound got much worse, and he thinks that maybe the loss of back pressure is cause his valves to slap or something of that nature... personally I'm not huge on the internals of the engine, I get in theory how they work and all that, but have had one torn down to nothing and put it back together... but yet I can fix just about thinking... funny how that works, anyway, I don't think the loss of back pressure has anything to do with the valves, but at the same time, it started rattling a lot worse... any input?

 

you are going to have a lot of problems just eliminating the cats. and your cts with canned tunes is not going to help.

the only way around is to get a custom programmer with tunes in it that allow for no cats. an off the shelf unit isnt built with those peramiters in it

 

hmm, that makes since, so then if I get a custom tune then I should be good on removing them... might sound like I plan...

 

any input on my buddy's chevy noise?

 

The Chevy noise. I'd have to be there, listening, using a stethoscope, using a stick to push against exhast system components etc to render an opinion.

As for your new truck, why not just run it a while? All that trouble to cut things up, trigger CEL, maybe make it run worse....

You are not going to see some dramatic increase in power or mpg anyway, assuming it's running correctly now. And, if you do get a CEL with it, it will point you towards the fault. Fool the ECU, and you could run rich or lean and not get a CEL. Serving suggestion.....