Magnaflow Catback Is On, Better Gas Mileage Too!

I installed the Magnaflow Catback on my 05 4Runner last night and it only took around an hour to complete. Very simple and straight forward setup. It's nice and quiet at idle, while under load it has a nice rumble to it. It's a superb improvement in looks compared to the ugly black resonator that used to reside in the rear. The best and most unexpected thing I have noticed so far is a 3mpg improvement in gas mileage. I didn't expect to see more then 1mpg if any. Needless to say with the high gas prices this makes me extremely happy. The bad thing is when I slap on my 22's later this week my mileage will probably go back down the crapper.

George.

very very nice. what kind of tools were needed to remove the old exhaust? I was thinking of installing my TRD exhaust when it comes in.

iFORCE said:

very very nice. what kind of tools were needed to remove the old exhaust? I was thinking of installing my TRD exhaust when it comes in.

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All that's really needed is a few basic hand tools. I used an impact gun to make things easier for me but a ratchet and some muscle will work fine. I also backed my truck onto some floor ramps to give myself additional clearance to work. You will need a 14m.m. socket and I think a 15m.m. as well if I remember correctly.

Start by loosening the two spring loaded bolts that mate the itermediate pipe form the muffler to the cat. From there use a little WD40 on the rubber hangers and remove all hangers so that the front of the exhaust drops down and allows a bit of additional clearance to remove the next set. There are 2 more bolts that connect the resonator to the muffler. It's located right by the rear axle. Dropping the front of the exhaust and removing all the rubber hangers will allow you a bit more clearance to work with these other 2 bolts.

Now in my situation the nuts on these last 2 bolts were spot welded to the flange from the factory. This adds difficulty as the bolts you will need to loosen are up top and you wont have a visual of them. It's a tight spot back there so be patient. Also in my situation these 2 bolts would not budge with 3 different impact guns or a manual ratchet with all the muscle I could offer. Your results may vary. To make things easier for myself I pulled out the sawzaw and just made two cuts in the rear part of the exhaust so I could pull it out from over top of the axle. I knew I would never put it back on so it was a no brainer for me.

Putting the new Magnaflow setup in was one of the easiest things I have ever done. Just hang the new exhaust in the factory rubber hangers, adjust it to your liking, tighten down the spring loaded bolts in the front, tighten down the supplied clamps around both ends of the muffler and you have a shiny new exhaust!

Someone else here may of had better luck with those back 2 bolts and if so hopefully they will chime in to help out. Good luck with yours.:

George.

:worthless

LOL, can't wait to see the pics. I've played with the idea of putting on an exhaust, but I've become accustomed to the quiet ride that I don't know if I want to lose that.

How is the highway drone (if any)?

I would never expect an increase in mileage from just a CAT-back. It takes a lot more than that usually. I would check your mileage over a long period of time (like a month) before making such claims.

Every vehicle I've owned I've done the catback

first due to the increase in milage. It pays for itself after about a year or two of driving. Thats next on the list for mine, been waiting for the right time to buy, should be soon, hopefully before 06. I leave for the desert in Jan and I want it on before I leave so the wife gets a little better milage while I'm gone.

T

greasefingers said:

I would never expect an increase in mileage from just a CAT-back. It takes a lot more than that usually. I would check your mileage over a long period of time (like a month) before making such claims.

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I didn't buy the catback for that reason but it was a nice side effect. I can only report what I know and that is a 3mpg improvement so far. My driving is done on a routine route daily. The gas mileage jumped up after I added this catback so I am reporting it to the members. I'm about to throw on my 22's so the long term won't be accurate as these wheels are heavier and will decrease my gas mileage once again.

sharp4runr said:

:worthless

LOL, can't wait to see the pics. I've played with the idea of putting on an exhaust, but I've become accustomed to the quiet ride that I don't know if I want to lose that.

How is the highway drone (if any)?

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I took this with my camera phone. Not the best quality but you get the idea.:

sharp4runr said:

:worthless

LOL, can't wait to see the pics. I've played with the idea of putting on an exhaust, but I've become accustomed to the quiet ride that I don't know if I want to lose that.

How is the highway drone (if any)?

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Sorry I forgot to answer your other questions. There is no highway drone at all. You can hear the exhaust under acceleration only. At cruising speed and at idle it's quiet. I'm in woodbridge so feel free to stop by and check it out for yourself.:

I have the Magnaflow also, but I'm not sure about any increased gas mileage. I need to take a trip and I will see. I can tell you that the sulfur smell not as bad. It still smells but nowhere near before. I would say it's about half as bad. It doesn't have that chocking/nasty smell anymore.

Koz

Koz said:

I have the Magnaflow also, but I'm not sure about any increased gas mileage. I need to take a trip and I will see. I can tell you that the sulfur smell not as bad. It still smells but nowhere near before. I would say it's about half as bad. It doesn't have that chocking/nasty smell anymore.

Koz

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Yep the sulfer smell is barely there anymore. I'm not quite sure why that is though.

The Razor said:

Yep the sulfer smell is barely there anymore. I'm not quite sure why that is though.

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I love that smell!:jester:
Some mods not only increse power but can increase your gas mileage if you can keep your 'foot out of it'. In some cases you are making it easier for you engine to inhale and exhale. That increases efficiency.

I have to preface that I'm a complete novice in the functionality of exhaust systems. I've been looking at the Magnaflow catback system for awhile now. I understand this package includes the pipes that connect the stock CC to the new muffler, tail pipe and tips. I also read the pipe diameter is the same as the factory pipes. Besides the new stainless steel look and muffler, how can this provide any gains?

Free-flowing muffler and you lose the OE resonator that sits in front of the tip...put a wadded up piece of paper in your mouth and go run, you can still breathe, just not as well...works for both ends...

I do understand more efficient airflow can increase mpg and power. I'm not trying to be difficult, I'm just trying to get things straight just in case I decide to go this route. Looking at the Magnaflow cat-back I would assume you'd get the same results with just swapping out the stock muffler and removing the resonator considering the pipes are all the same. That would seem much cheaper than purchasing the entire cat-back system. Am I missing something?

Surge97 said:

I have to preface that I'm a complete novice in the functionality of exhaust systems. I've been looking at the Magnaflow catback system for awhile now. I understand this package includes the pipes that connect the stock CC to the new muffler, tail pipe and tips. I also read the pipe diameter is the same as the factory pipes. Besides the new stainless steel look and muffler, how can this provide any gains?

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well I am to believe they are 1/2 bigger in diameter then stock pipes , I have the catback and the cold air K& N , I notice an increase in power , but have read other people say there is no more and its in your head , I have always believed bigger in and bigger out increases power , I live in Venezuela where the gas is 50 liters for a dollar so we don't check mileage , we keep the foot into it , the sound with the two add ons is awesome