Alright so there are a ton of threads but most never actually have a full answer.

The cats rattle on my 01 5.4 and this summer I plan to fix that. Now I figure for cheapness and sound I might as well go with the magnaflow cats and just a single on each side but I dont want CEL's obviously.

Troyer performance says to use the 94306 as do many posts but a good number of other posts say use the 94136 as it has an o2 bung welded in reduceing the chance of CEL's.

Survey says?

 

I have a 1997 f150 4.6 and I was thinking the same thing as you so I took my truck into my exhaust guy to see what he would say. He told me the pre heater cats were fine and it was the big cats that were making the sound but I said just get rid of the pre cats and do 1 single cat on each side in place of the large ones. I did his generic high flow cats(nothing special) and that was just done last week and I have had no CEL come on. I think youre good to go man.

 

Ratherb did you notice any mpg/performance gains yet?....ive heard that they dont give you any but im just curious

 

hey hunter, wish I could give u the info you are looking for but my motor is knocking haha. Just pulled a donor motor yesterday to put in my red rig so I couldnt tell you performanceat all as I baby it right now but I have put a couple hundred k soo far and did not notice any fuel improvement at all. Nothing worse than a cel alays on though.

 

Perhaps if you were in the exhaust forum you would have more luck.

I'll provide a little info or straiten a few things out that's been posted so far. You have 4 complete converters. Upstream and Downstream. There's no such thing as "Pre-cats". Some board sole made that up a long time ago and it stuck for some reason. It does have a ring to it tho. Never count on an exhaust shop to know your specific system. They know enough to fool you and that's about it, most of the time. Not all are like that of course. BTW - Pre-heaters are O2 sensors(2 white heater wires) that pre-heat to 800c. This has to do with open/closed loop operation, switching and so forth.

I have explained all this many times in the exhaust forum. Search that forum only and there's a wealth of info posted by quite a few members who are knowledgeable in this area. So I'll skip the rest of that crap lol.

That's what you have.
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LT Headers are the cheapest route if you do you own work. Then OX compliant High-flows attached direct to the collectors. It's cheap because it's to do yourself and LT's can be had cheap. New High Flow performance cats are free, if you know how to make it so. You also add a nice bump in power and torque going the cheap route.

If you take it to a shop, you can loose all those benefits.

PS headers, 200+
Magnaflow HF OX compliant converters, FREE
Mufflers, X-pipe or what ever after the Y is up to you.

That's the cheapest with the best benefit in sound and power.

No you won't get a CEL/MIL IF the Y is tight. The Y must be leak free. Other than that, your well within programed parameters.

 

I have headers on my 440 Belvedere and didn't want the hassle on my daily driver, plus knock on wood no busted studs on my exhaust manifolds after 12 years of Canadian winters figure if I decide to unbolt them it might not go nicely.

 

The rattles are prolly cuz the maggie hiflow heat shields are not always welded properly. I've had to have the one on the pass side rewelded twice. I have the 94036 on mine.

 

His OE cats are rattling.

 

What does the rattling sound like? I have a clicking sound that is driving me crazy and cant figure out where its coming from!

 

Right. They rattle once they ignite/explode a few times and the brick busts inside. Derives from a misfire at some point in the past. Fuel washes over the advance coating, then boom. Well, not "boom" lol. You usually won't here that happen.

The heat shields vibrate or chirp once one of the spot welds begin break. They break all the time at the spot welds. Ford has a TSB on the issue that states to use 7" band clamps around the shields lol. - True!

The heat shields can chirp so bad, it sounds like you have some prehistoric bird nesting under the truck while in line at the McDonald's drive thru.. Very annoying. No telling what's in the bag when I'm pulling away.