I just replaced my stock exhaust on my 2005 Screw 5.4 lariat with a Magnaflow SIDO with ss tips. I have immediately noticed a difference in acceleration and shift changes, where else should I expect changes? Horsepower, MPG, etc.?

 

With a simple cat back you're lucky to notice anything besides noise.
Now if you added long tubes and high flows bundled together with a custom tune you would notice a good amount of change.

 

I plan on getting a tune once I had some more modifications to where a tune would show its affect on the truck and I'll probably end up replacing the SIDO with a DIDO later on with some high flow cats. I bought the SIDO when I first started looking around for an exhaust system and I didn't know too much about it. And what do you mean by long tubes?

 

Long tube headers...

 

Kinda pricey as far as "money spent to horsepower gained ratio" goes... But if you really want a FULL aftermarket exhaust, they are a must do....

 

I don't tow much other than our boat and a trailer a couple of times a year so I'm not looking for a lot of horsepower gain. I mainly want an exhaust better than my stock that sounded nice and if I gained some MPG I'll take it

 

A di/do is gunna get you some gains up high in the rpms. unless you do mandrel 2.25 exhaust..
Honestly don't go into modding a truck for mpgs. Its a crap shoot in you're gunna get any better.

 

I'm glad you noticed a change!

 

Stickers....don't forget the stickers....and the wale-tail too!!!!!! (GRIN)

 

Yeah I put the "Borla Exhaust" sticker on my back right window and I IMMEDIATELY noticed better power under throttle and +5 mpg's.

 

Of course how could I forget to add stickers haha I actually don't have any currently. As soon as I replaced the faded ones on my old truck I got my new one so its still naked right now. And whats the wale-tail?