Saturday, January 7, 2017

Fixing a Muffler on a 2007 Toyota Yaris

Difficulty Level (Easy, Medium, Hard, Insane):

A coworker asked me if I could have a look at her 2007 Toyota Yaris because her muffler fell off. The history behind this repair is that a couple of years ago, the muffler rusted off and she was stranded in the middle of nowhere on a Saturday so she found a welding shop that did a quick and dirty job welding it back together.

However, the salt, winter and generally harsh road conditions up here in Canada took its toll on the pipe and rusted it off again. Unfortunately, the way Toyota designed the exhaust system was with no joins/links and replacing/fixing it the way they would recommend it would cost about $1500 bucks.

Needless to say, my coworker was looking for an alternative way of fixing the vehicle. After having a look at it I devised a plan to buy a transition pipe at canadian tire and try to make it work in such a way that the muffler could be taken apart again in the future without having to cut through the pipe.

After I cleaned up the old weld on the muffler, I used my MIG welder to build up the connection point so I'd have some solid metal to weld the new pipe to.

Then, I went under the vehicle and cut off the last 2.5" of rusted pipe and used an exhaust pipe expander to un-dent the pipe. Once that was done came the rather lengthy part of fitting the old pipe to the new pipe to the old muffler.

Unfortunately, I discovered that when they did the first fix a few years ago they welded the 2 foot pipe a bit crooked which made the muffler and the pipe not match up properly. The pipes were off by over 2" and I suspect they just forced it together and did a quick weld. That is why I suspect the weld failed after just two years.

After some thinking and trying a bunch of different things I decided to keep the pipe the way it was but twist the muffler by about 2", then cut the new pipe at an angle so that there wouldn't be any stress in the weld.

Once I dry-fitted it, I did 3 tack welds between the new pipe and the muffler, take it off and took it to my work bench where I finished welding the new piece of pipe to the now built-up area of the muffler. Then, all that was left to do was to apply some muffler cement to the inside and outside of the join, slip them together and use a u-shaped muffler clamp to hold it all together.

Over all it went well, I worked into the wee hours of the night but I got 'er done so I'm sure my coworker will be happy about that and I don't suspect there will be any issues with the part I repaired for at least 4-5 years if not more


The rusted off remains of the exhaust pipe

Holy, so holy
After cutting off 2"; I ended up cutting off another 1/2" later

The rusted end pipe what was welded to the muffler

Another view

The old pipe they welded to the existing exhaust 2 years ago

Using a pipe expander to round out the last 2" of pipe

The muffler pipe expander

I had to weld the muffler adapter at an angle to match up the existing pipes

Another view of the weld

Some muffler cement sealed up any small leaks

The finished job after it was clamped together

Car ramps
Impact wrench
Socket set
Ear & eye protection
Measuring tape
Soap stone marker
Jiffy marker
Work lights
Angle grinder
Bench vise
MIG welder
MIG welder cart

One 1.750" inside to 1.750" outside muffler pipe adapter
One 1.750" u-shaped muffler clamp

4-5 hrs


Well, it looks and sounds great. I'll post an update in a couple of years (if I remember to do so)


Rolf Nilsen said...


I did the mistake of measuring and welding off the vehicle last time I did this. Next time I'll do as you did and tack it while on the vechile.

If she would apply some linseed oil to the underside of her car once or twice a year she would probably not have as many issues as this. The underside of the car looks a bit "dry" :-)

(never mind the smell)

Post a Comment