View Full Version : My First DIY Exhaust (with pics)

10-20-2009, 04:52 PM
I didn't know where this belonged so feel free to move it if it's in the wrong spot.

The exhaust on my MR2 has always been a problem. When I first got it it had the stock 4A-GZE manifold WELDED to the midpipe, then to the flex pipe, then to a MK2 MR2 turbo muffler. The thing was far too loud and didn't sount right. Well one day I was driving on the highway and the exhaust got louder and louder and then was accompanied by a scraping sound. The rear most drivers side hanger had broken and the muffler was dragging. I managed to hang it up until I go to the next town where a local muffler shop put on a 1985 MR2 muffler on it. This worked for a bit but it started to get loud again. I took it to the shop to have a new flex pipe put in and that worked for a while. Recently the exhaust got loud again and I checked and found that the flex pipe they had put in was simply one of those cheap "U-Fix-It" clamp on pipes that had been welded in place. So I decided it was time to fix it once and for all.

I tried to find a new manifold for the car, but I couldnt get one at a reasonable price. I soon realized that I was being silly and went and looked at the manifold on my spare engine (JDM 4A-GZE). It looked more like a header than a manifold but it looked like it was in good condition so I decided to use that. I took it to a local shop to have it ceramic coated.

Next challenge was the midpipe. At first I thought that I was going to have to build one, but then I found that one of the spares from my fourth gen Celica fit just fine.

I found a post on a local automotive forum from a gentleman who had a performance shop that is now closed but had mandrel bent pipe for sale. So I picked up some 2.25" mandrel bent pipe for very little money.

Next stop was a local muffler shop which agreed to sell me a resonator and a flex pipe.

I then picked out a Magnaflow muffler from an online store and ordered it.

Finally I went to Toyota and purchased all the nuts, studs, bolts, and gaskets for the entire exhaust, hangers and all. Then I waited for all the parts to arrive.

I started work on the Friday after all the parts were in the garage. The first thing I did was remove the muffler. That was fairly easy as the exhaust pretty much broke in half at the "flex pipe". There had been some custom (not so nice) mounts made by the previous owner that were bolted and welded to the car. I removed these and exposed the stock bolt locations. I used a tap to rethread these. I had the stock exhaust hangers from my parts car so I used those.

I then removed the EGR and O2 sensor and unbolted the manifold from the car. I could not get it our as the midpipe was still welded to the manifold. I didn't have a sawzall so I had to bolt the manifold back up and chip away at the midpipe with an angle grinder. Finally I removed enough that I could get the manifold off the car. I found that the manifold actually had a crack in it.

Next I tried to put the header on. It was tight but once I removed the oil filter it went in fine. Unfortunately the oil filter no longer fit. I was a little confused until I looked at the engine I pulled it off of. For some reason Toyota hadn't put the oil cooler on that engine so the oil cooler plate wasnt on the block. Not wanting to remove the oil cooling I opted for an oil filter relocation kit. The oil filter is now on the firewall.

With the header in place I used some old hardware to bolt the midpipe on. I installed all the hangers. I then put the flex pipe in place and tacked it to the mid pipe. I tacked the hanger on the other end of the flex. I then used jackstands and a measuring tape to put the resonator and muffler where I wanted it. I then cut the mandrel bends to fit and tacked everything in place.

Once that was done I removed the exhaust from the car and welded it up properly. I am by no means a proffessional welder but my welds are solid and leak free. Lastly I painted the exhaust with header paint and put it back on the car.

It's still louder than I would like, but no longer sounds broken. Inside the car is the biggest difference. Conversation at highway speed is once again possible.

As promised, pics:

Old manifold and muffler:

Old manifold welded to midpipe:

Crack in #4 runner:

New parts:

Tacked up under car:




10-21-2009, 12:25 AM
gewd job dood!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1 111111111111111111oneoneone

10-21-2009, 12:49 AM
Looks great!

10-21-2009, 02:46 AM
Great job! That's really good work.

10-21-2009, 04:21 PM
Thanks for the kind words!

Okay, so this was the first drive. The car had been warmed up and cooled, then warmed (part of the curing process for the paint). The first time I rev it up a bit the engine doesn't fire on all cylinders (still tracking that down), but after that it smoothes out. Enjoy!


http://i150.photobucket.com/albums/s117/Berg9987/Exhaust/th_MVI_0569.jpg (http://s150.photobucket.com/albums/s117/Berg9987/Exhaust/?action=view&current=MVI_0569.flv)

10-21-2009, 04:40 PM
Damn that thing sounds great. Nice work on the exhaust.


10-21-2009, 04:57 PM
Looks good, better than the previous DIY job it had.

Wicked Toys
10-21-2009, 08:26 PM
Awesome job, looks good.

10-22-2009, 10:30 AM
And you did all that exhaust work without a hoist. Good job man.

10-22-2009, 03:36 PM
Thanks again for the kind words guys!

And you did all that exhaust work without a hoist. Good job man.

Yeah fortunately the exhaust run on the MR2 is short enough that all you have to do is jack up the back end of the car. One day I'll get to build a longer one for my Celica. At least now I have the confidence to do it.