have a 2013 5.0 screw 4x4 with 90k. Im the second owner. I have had it almost 3 months. About a month ago I had the stock muffler cut off and a new magnaflow single 3" in with single 3" out. Ever since then my transmission has acted funny. Its like it is holding gears longer. I notice espically in the lower gears. Could the exhaust have anything to do with the transmission shifting? I have unhooked the battery a couple different times so the truck could relearn the shift patterns but its still the same.

 

Some one will hopefully chime in on this, but could it be with the new exhaust tone it sounds like it is. Not at all doubting or calling you crazy but a new sound/noise can make the mind wonder, Ive had it happen to myself many times.

 

It totally could be the sound just makes me think it is..i have no idea. I just know i did not notice it until the exhaust

 

Im betting that thing can beller in the upper Rs, and Im thinking before the muffler you never paid attention to the shift points, but the extra GGGRRRRR.....got it...lol

 

You're not crazy. Mine did the same thing. It's because of the change in power band. The low end torque drops off pretty bad.

I hopped in my buddy's truck which has stock exhaust the other day, and the low end torque that he's got is immediately noticeable vs. mine.

My truck also shifts differently on E85 fuel, for basically the same reason. More power means different shifts.

 

It's hard to imagine that there would be that big of a noticeable drop in low end torque from a muffler welded in. Maybe +1 either way. I think sometimes the sound change makes people feel this way. Not discrediting you but I would refer to dynoing before and after for actual power results.

 

I would have to lean more towards the sound, or maybe subconsciously driving it different.
Especially when you went single in/single out.
If you went more radical, like no resonators, exit before the wheels... I could see a loss then.
Also did you leave the battery unhooked overnight? That's the best method, so I'm told.

I've put exhaust on every truck I've owned, except for my 14--5.0.
People keep asking if I put exhaust on this truck. So, since it apparently sounds like it's aftermarket, I see no reason to change it. Besides I prefer the intake *growl over the exhaust note...

I will add though. The best aftermarket exhaust set up I had, was when I did a single in and single out Magnaflow on my 2010. Perfect all around.

Throw a new air filter in, for the hell of it. Now that will surprisingly affect performance. That's a whole other thread tho.

*I bought a 2017 Triumph Speed Triple motorcycle. Aside from that thing being crazy with the amount of torque in every gear, at any speed. My favorite thing about it is, the intake sound. Very similar to our 5.0's.

 

I'm another vote toward the sound tricking your senses.. same reason people think that simply removing the stock muffler (straight through design) and replacing it with another straight through muffler using the same diameter pipe magically made their truck faster.. It sounds faster thus your brain thinks its faster. I'm guilty of this as well.. hell, I still want exhaust, just so I can think my truck is faster.. lol.
If you did a full exhaust or changed the pipe routing or size, then yes, you may notice a minor difference on the dyno.
Here is a video for reference..

 

I know i dont have anymore power. My concern is that say it use to shift at 2500rpm and not it acts like it starts to shift at 2500 but feels like i have a manual and pressed the clutch in to long and then shifts like 2 seconds later than it should.rpm numbers are not exact,just using 2500 as a reference point.does how i explained it make sense?

 

Mine definitely wasn't a sound change. It was a driveability change. Trans. immediately started shifting at different times. It's as if the shift tables were altered, even though the programming wasn't changed by a tune. The truck really wants more RPM and will downshift all the time now. In the same truck with stock exhaust, the torque is noticeable and the truck will build speed without downshifting. It will take more throttle input to create a gear change. I noticed it immediately after leaving the muffler shop.