Been trolling the forums for awhile now and finally joined up today. Bought an '07 5.4 FX4 Scab back in August, 45,xxx miles. Been working on a few visual mods. The only performance mod thus far is the DWV intake mod I did shortly after getting my truck. My plans are for a new exhaust, Gryphon tuner, e-fans and UD pullies in that order. I'm already set on the Magnaflow SI/DO exhaust #16523, and will be ordering as soon as possible. My question is while I'm doing the cat-back exhaust would it be worth the extra time and money to install the Magnaflow cats and Y-pipe as well?? Correct me if I'm wrong but if I replace the cats I should also replace the Y-pipe? And The Y-pipe I would be replacing is the one that runs the dual pipes coming from the cats into one which connects to my muffler? And, last question, would the cats and Y-pipe from Magnaflow be a simple bolt-on like the exhaust, something I could do myself with no welding? Sorry if I'm being confusing and thanks in advance for any help/suggestions!!!!!!!!!!

 

If you have the resources you might as well install Long Tube headers if ur gonna be down there cuttin stuff up. As for the Y and cats being direct bolt on I really wouldnt recommend clamping the cats cause the clamps tend to leak and an outside leak will ruin ur cats pretty quick. I put a band clamp where the cats slipped onto my header collector and threw a P0156 code cause of a leak :/. You also might consider that you would have to custom bend the pipes to fit the maggie Y (I think, not sure about exhaust routing on an '07 sorry). . I'm not sure about performance w/ the maggie Y but it sure makes ur exhaust sound better IMO.

 

And welcome to the site!

 

Thanks for the info. man!! I'm not really considering LT's, at least not yet . From what I understand the '07's have pretty efficient stock headers anyway. I didn't think I would have to mess with custom bending. I thought installing the Magnaflow Y-pipe and cats would be pretty much direct fit. For what they will do for my performance I will probably stay away from the idea of cats and Y-pipes and just stick with the Magnaflow cat-back system for now. Thanks again for the help!!

 

advice from an old man. leave it stock except for intake/exhaust. all the F150s need is a little more sound. performance gains; intake maybe 9-10hp. exhaust only 5hp. together maybe 12hp. don't experiment like i did. make the right choice the first time. corsa or borla. neither has drone. the borla is just a little more agressive than the corsa. the corsa almost silent at cruise. the borla is with you all the time. anything else is going to drone.

 

Thanks for the advice, but I'll probably stick with the Magnaflow SI/DO system. I've heard plenty of good things about this system and haven't heard any complaints regarding drone. Have you been hearing different? Plus I like the fact that the system is stainless steel, under $500, and I can save some cash to put towards my Gryphon by being able to bolt it on in my driveway.

 

Hey BT,

In your first post you said you have a 5.4, but the mag kit item you want, 16523, is for the 4.6L and I don't know, but I would say that they are probably not interchangeable. Here's the link for that model on magnaflow's website.

http://www.magnaflow.com/02product/d...rtnumber=16523

On magnaflow's homepage you can type in your vehicle info and it will bring up all the models and configurations that will fit your truck. Good luck!

 

Well slap me silly and call me Susie...forget what I just said.

It seems that your part number 16523 is just fine for the 5.4L. I went in and typed in your truck info and that part number came up as compatible, but if you just type in the part number, it only pulls it up for the 4.8L for some reason.

Sorry for the confusion. Well I guess I was the confused one...

 

Dre23, come on man you had me all scared there for a second.....lol. As much as I've been researching exhausts I would have cried if I just now found out that part# didn't fit my 5.4. No worries man, I appreciate the heads up...............even if you were a little confused, hahaha.

 

Yeah, I'm really sorry man. That's what I get for trying to help out, huh? lol. Well sorry for the scare...Next time I'll do my full due diligence before speaking!

 

If you know your exhaust systems, -Corsa and Borla are a grade above Magnaflow. That's just what it is, - if your picky. Their all good. Go with what you can afford, - Magnaflows are alright for the price.

 

I went ahead and ordered the Magnaflow #16523 today. I think I'll be happy with the results. I plan to use the included hardware to bolt it on in my driveway. Anyone think it would make much of a difference if I had it welded as opposed to bolted together??

I appreciate all the help and input...THANKS!!!

 

The Magnaflow cats and Y-pipe will require more indepth installation. You have to cut the OEM cats and Y-pipe off and weld them back in or else there will be leaks. The cats also require you to remount the O2's bungs after the new cats. So you'll have to drill/cut a hole and weld on the bung.

 

Gotcha, and maybe I wasn't clear in my earlier posts but I've decided against installing the Magnaflow cats and Y-pipe. I'm going with just the Magnaflow cat-back exhaust system..........for now at least. The exhaust system is a simple bolt-on, but I now alot of guys have had theirs welded together. My question was pertaining to whether it made much of a difference to have the exhaust system bolted together or have it welded.

 

That sounds smart. I would probably just bolt it, but use the band clamps for minimal leakage. It will leak, but very little, - no performance difference over welding. Just don't use the regular cheap muffler clamps (rod clamps) if you can help it.