MagnaFlow 15145 MF Series Performance Cat-Back Exhaust System
Step by Step Installation and Instructions of the MagnaFlow 15145 Cat-Back Exhaust System.
This install is on a 2014; however, this exhaust will fit on other models. This is a very simple install and can take under 3 hours if you have two guys.
You will get the most out of this exhaust system if you install a cold air intake (CAI).
The CAI combined with an aftermarket exhaust will open up the airflow through your engine, thus increasing the overall performance. While you are at it, just install the entire list of performance mods for the 4Runner.
- System for 5th Gen 4Runner: Check Today’s Price
- TIP FINISH: POLISHED
- MATERIAL: STAINLESS STEEL
- 14mm Sockets
- 15mm Sockets
- Flathead Screwdriver
- Truck Creeper
- Jack Stands
- OEM Spare Tire Tools
- MagnaFlow_Instruction_Manual_5th_Gen_4Runner (PDF)
- Warning (PDF)
Step 1: Jack up Truck
You will want some car creepers or something to move around on once you are underneath the truck. This makes for an easy process for getting in and out from underneath your 4Runner.
Step 2: Unbolt Exhaust from Y-pipe
Start by unbolting the OEM 4Runner exhaust from the Y-pipe under the center of the truck. This is the piece that connects the actual muffler to the Y-pipe. At this point, you do not want to actually remove the exhaust or even the bolts. Leave the bolts connected. Right now we are just loosening the connection from the exhaust to the Y-Pipe. We don’t want to remove the bolts because we will need to remove two more bolts that are connected to the exit tubing.
In V6 and V8 engines where there is more than one exhaust bank, ‘Y-pipes’ and ‘X-pipes’ work on the same principle of using the low pressure component of an exhaust pulse to increase the velocity of the next exhaust pulse
Step 3: Unbolt Exhaust from Exit Tubing
We will need to remove two more bolts that are connected to the exit tubing. At this point, you want to loosen these bolts as well. It is important to keep the bolts on that are connected to the Y-Pipe as the whole system moves when you are trying to unbolt the exhaust from the exit pipe.
You remove the bolts from the Y-Pipe (like we did), you are going to have a hard time getting leverage on unbolting the exhaust from the exit pipe. We had to put the bolts back on to get enough leverage to remove the second set of bolts pictured below.
After you have loosened the 4 bolts from the Y-Pipe and the exit pipe, you can now remove all 4 bolts and set the aside.
Save the bolts from the Y-Pipe section, you will need these to install the new MagnaFlow Cat-Back Exhaust on your 4Runner.
Step 4: Use WD40 to loosen up the Rubber Connectors (Rubber Isolators)
Next, you want to remove all 5 of the rubber connectors (rubber isolators) that hold your exhaust on and prevent your whole truck from shaking when your engine is running. Pictured below are all 5 rubber connection points.
VERY IMPORTANT: Do not damage the rubber connectors, you will need these to install the new MagnaFlow Cat-Back Exhaust on your 4Runner.
To loosen the rubber connectors, use WD40 and a very small flathead screwdriver. Use the flathead screwdriver to open up the rubber connectors in between the rubber and metal. Spray the WD40 in between these small spaces and slide the rubber connectors back and forth until everything is sliding around nice and free.
VERY IMPORTANT: Do not remove any isolators at this point.
Rubber Isolator 1
Rubber Isolator 2
Rubber Isolator 3
Rubber Isolator 4
Rubber Isolator 5
Step 5: Remove OEM Exhaust
After you have greased up the rubber isolators with WD40, you can now remove all rubber connectors and remove the OEM 4Runner exhaust.
Step 6: Remove OEM Pipe
VERY IMPORTANT: Note that you will have to lower the replacement tire in the rear of the 4Runner to allow the old OEM exhaust pipe to exit and be removed. If you do not lower the tire, you will not be able to remove the exhaust pipe (yes, this happened to us as well). Hopefully, this helps you expedite the process a little faster.
Step 7: Ready for Install
Step 8: Feeding Tail Pipe
The first section of the new exhaust you want to install is this crooked looking piece of exhaust tubing, the tail pipe. This will go straight up and over the frame.
Step 9: Installing the Muffler
Once you have the exhaust back onto the rubber connectors, you can grab the two bolts that you disconnected from the Y-Pipe and bolt those back onto the new system.
Step 10: Installing New Tail Pipe (New Clamps)
Once you have the new exhaust bolted onto the Y-pipe and connected to all the rubber isolators, you can now start to clamp on the remaining two clamps in the rear and exit of the system.
That’s it! This is a very easy install if you have a couple spare hours in your day. It took us around 3 hours from opening the doors to having the new exhaust on.
You want to check out the exhaust in a couple days and make sure all of the rubber isolators are still in place.
Looking to add an aftermarket exhaust. TRD Pro exhaust, Magnaflow or Borla?
Now that it’s been a while, how much (if any) drone after long term use? Any worse than A/T tire and CAI that I have already?
After chopping the exhaust all the way back to underneath the cab (just above the rear axle), it does drone quite a bit. Level 1-10 with 10 being super annoying, it’s about a 5. I can live with it, but sometimes I have to let off the gas so I can hear what my girl is saying. So hopefully that helps. But again, I have mine cut off at the axle. With the exhaust in the bolt-on placement, it was about a level 2 drone (out of 10).
Installed my Magnaflow without any problems, at first. After driving a bit, noticed a sound almost like low bass from a subwoofer when idling at a stop. Was semi loud inside, but could barely hear it outside. Turned out it was tapping a bolt by the heatshield, I had it cranked too far over to one side. I would advise to check the end of the exhaust as it comes out the cutout in the bumper and make sure it is centered. Mine was way over to the left.
What roof rack you have on this?
That was the Rhino-Rack Pioneer Platform.
Just installed the magnaflow catback exhaust on my 2011 4Runner limited. This page was very helpful and it helps to have more than one person work on it. The only problem I had was getting the bolts off of the exit tubing from the pipe coming from the muffler. Just ended up cutting the pipe in 2 spots instead of trying to remove the rusted bolts. Other than that no problems and love the new sound. Great product.
Wondering if anyone knows what the difference is (other than price and exhaust location) of the MagnaFlow 15145 and 15584? Going on a 2015 TRD Pro. Why is there a price difference and is there an advantage to rear exhaust over side exhaust? Thanks—
Brenan, do you know of anyone who has installed the MF 15584 side exit exhaust on a newer 4R? The MF website says it fits something like the 2011, but I’ve seen on YouTube where someone did it on a 2016. I’m guessing that MF doesn’t list it as compatible because you have to cut that rubber/plastic piece at the exit point as you did on your rotten egg smell post. Any thoughts? I’m thinking about installing on my 2018 ORP. Thanks
I installed the MF today on 2018 SR5 and noticed a hum when it idles after turning on. It sounds like a low subwoofer hum. Is this normal? Thanks for all the knowledge!
You may need to bend back your heat shield. It’s super simple and can be done with your hands, just pull it back away from the exhaust about 1-2″.
I just installed the Borla today on my 5th Gen Off-Road Premium, but the exhaust tip touches the rear valance and has started to melt the paint off the valance, so I am thinking about returning it to get the Magnaflow, but will I run into the same problem? Do you know if the Magnaflow exhaust tip touches the rear valance on the Off-Road Premium or TRD Pro models? Also, do you have any suggestions for the Exhaust Tip touching currently with the borla? It seems like it would only need to be about a 1/2 inch to an inch lower to not touch
I would take it to a muffler shop and just have them take it down an inch if you really want to keep it.
Does anyone know if the mf cat back will fit with kdss?
Yes, it does. We installed the Mf cat back on our 2014 with KDSS.
I just installed my own cat back MF. 5th gen. I went the other way and followed MF instructions and started at the front of the vehicle. I would also suggest 3 things.
1 – Remove the tire heat shield. It will make it easier to remove the stock tail piece.
2 – When assembling the pieces together, make sure they are pushed together as far as they
can go. This will give you more space at the heat shield and screw and hopefully eliminate any rattle.
3 – When installing the tail piece, put it on the hanger first.
I would say it is not much louder than stock, very little difference in sound. It does produce a better pedal feel.
Any experience with going to dual exhaust after Magnaflow muffler?
Have shop that will bend the pipe
Kevin, no experience with a dual system on the 5th gen. Let us know if you have a shop do it, would love to see an install or overview.
I installed my Magnaflow exhaust last night. Being a family man, I need to do any mods after the kids are asleep. The biggest problem with this is I need to be very conscience of noise. If you have never tried making your 4R awesome in silence – just take my word that it takes a lot longer then it should to get anything done.
I had a terrible time trying to get the bolts undone from exit tube. I just could not get enough torque on them. After laying on my back for awhile (in silence) I decided I was just going to cut the pipe. How do you cut a pipe quietly? I dunno. I tried to grab my reciprocating saw, put a fresh diablo metal blade on. The concept was to run it slowly. LOL. Not happening.
Okay, lets try a fresh metal blade on a jig saw and run that slowly. Nope.
Fine, lets just use a hack saw. Hey, this is working. I can just do it slow and its pretty quiet. Problem is, getting the right angle to engage more of the blade is difficult. Maybe I should try to just hold the damn blade with my hands. Yup, this is working. Maybe 45 minutes later I have successfully cut through the pipe!
After wiggling out the rest of the parts of the OEM stock I figured out that I still needed to take those stupid bolts out. At least I could get enough torque on them this time.
Install went smooth, test drive went okay. Drove a couple miles to the gas station and was getting the infamous Magnaflow rattle many people talk about. I went to bed mad, woke up to ask about returning the product to the Amazon dealer I got it from and got ready to call Magnaflow to complain. Instead, I looked at the 4R sitting in the driveway, jacked it up and took a look. I could shake the exhaust tip from side to side and make the pipes just barely tap a screw coming out of the heat shield.
I loosed a connection or two, pulled super hard, and re-tightened the brackets. I’m guessing I pulled the exhaust forward 1/8″. I drove to work. No rattle.
Success. For now. I’ll keep an eye on it and hope for the best. If it does start to rattle again I am going to grind that screw down and see if that fixes things.
Combined with my K&N intake, I have gone from about 17mpg to almost 21mpg and she sounds pretty mean. Pending the rattles stay away I think I’ll enjoy these pipes.
After driving it I need to inspect the install. I hear various rattling and squeeaking. Magnaflow said to inspect there is no rubbing and everything clears heat guards.
Yeah, there is a heat shield in the back. You may have had to take this piece off when installing the exhaust. Look at where the heat shield is making contact with the exhaust. Take the heat shield off and bend the shield away from the exhaust. It should not take much, maybe an inch or two. Use a set of vice grips and clamps to bend the shield.
I did the install this past weekend and it was relatively easy. The only issue I had were getting loose the two screws form the exit pipe. The front two that are spring loaded were no issue. I must have been at just those screws off an on during the day for about 4 hours even after lubrication. But one they were off the rest of the installation was a no brainer.
SYS C/B 2012 Toypta 4Runner 4.0L,2.50″ Stanliess Steel Tubing, 5X11X22″ Muffler, 4.0″ Tip
15145/15145MF Cat Back System Mandrel Bent.
I just got this yesterday and the box says 2014. Even when I called Magnaflow they directed me to this model. I am doubble thinking it. Will this fit the 2017 SR5?
What is the model number on the box?
Why did you choose to go with a Magnaflow over other brands?
After reading for hours and probably months in the forums, it came down to the sound. As most systems; Flowmaster, Borla, and Magnaflow are similar in performance, the sound of each is very different. I thought the Flowmaster would have been too loud for my taste. Also, I thought the Borla Catback exhaust system would have been a little underwhelming for my taste.
What benefits do you get with this mod? More HP? Better MPG?
Obviously better sound, the tip looks bad ass. From an actual HP perspective, I have not run any tests but I honestly do feel the difference when I get on it. We did not put in on a Dyno, so hard to really tell.
Yeah, the exhaust is much larger so I definitely get better exhaust flow. Everything back from the Cat is going to be easier on the engine.
In terms of MPG, I don’t know what to say… it’s a 4Runner. I have not noticed a huge difference.
I can say with the sound being better, I do get on the gas a lot more often and do not regret installing the exhaust overall.