It's been too long since I've been running my Cobb stage 2 and now it's time to tackle on the downpipe. This install DIY should help people to gain some confidence when installing this mod. Although I tried to be thorough with this DIY, should a question arise, feel free to ask! Also, if you're still not confident about doing this yourself with the DIY, please consult your local mechanic. I will not be responsible for any damages that have caused following my tutorial.
Tools needed
1. 8mm, 10mm, 12mm, 14mm, and 15mm socket wrench, combination wrench, and ratcheting wrench (HIGHLY recommended)
2. Set of extensions, universal joint (recommended), and a breaker bar
3. Ramp or jack with jack stands
4. Penetrating fluid (i.e. PB Blaster or Liquid Wrench. NOT WD-40)
5. Set of 22mm O2 sensor wrench
6. Set of philips screwdrivers
7. Set of torx screwdrivers
8. Gloves and eye protections
1. Remove the Wipers and upper cowl
If you haven't already, pop the hood and let the car cool. You don't want to work on the exhaust when it's hot. Let it really cool and begin by removing the wipers. Remove the wipers by removing the rubber cap and the 15mm nuts underneath. Before removing the wipers, mark their location with a tape. If you have a dirty car like me, the marks will be quite visible without the tape. After the wipers are gone, remove the upper cowl by removing clips using flat head screwdriver. After all the clips are gone, just pry the cowl with your hands.
2. Remove the headlights
Now it's time to remove the headlights so we can reach the lower cowl. Start by removing 2 torx screws and 1 screw push tab. Once the screws are out, pull the headlights up and you'll hear a loud noise. This is normal. Once the headlights are out, unplug the harness and set it aside. Repeat the same thing on the other side.
3. Remove the lower cowl
Once the headlights are out, remove 4 10mm bolts (2 on each side) that is holding the cowl in place. Once the bolts are removed, just pull it out then set it aside.
4. Remove the upper intake piping
Now, there should be plenty of room to work with the intake. You just need to remove the upper piping in order to have space. Start by loosening 1 worm clamps on each end with flat head screwdriver or 8mm wrench. Once the clamps are loose, remove the bracket that's holding the intake piping with 10mm and 14mm bolt. Don't forget to remove the breather hose in the back of the intake (not pictured), and remove the intake piping.
5. Remove the upper O2 sensor
You should have a clear view of the upper O2 sensor. Soak it with penetrating fluid then use a O2 socket wrench to remove. I did it by combining O2 socket, extensions, universal joint, and a breaker bar to break it lose. Remove the O2 sensor and set it aside.
6. Remove the heat shield bolts
Now the fun part. Start by removing the heat shield bolt on the exhaust manifold. They are all 8mm black bolts and 2 of them can be reached from top and other 2 from the bottom. Just remove the top 2 bolts for now using ratcheting wrench then set it aside.
Now remove bolts that's holding the downpipe heat shield. They are all 10mm silver bolts. 4 of them can be accessed from the top. There's one more bolt that can be accessed from under the car.
7. Remove lower O2 sensor
Now under the car, you can remove the lower O2 sensor using a socket wrench and O2 socket. Be sure to soak it with penetrating fluid before tackling it. Once it's removed, set it aside.
8. Remove downpipe bracket
While under the car, remove the bracket that's holding the downpipe which is attached to the rear motor mount. Remove 4 13mm nuts and the bracket should be free. Set it aside.
9. Remove downpipe heat shield
After removing the last 10mm bolt from under the car, downpipe heat shield should be free. This can be a bit tricky but it can be removed under the car. Start by rotating the heat shield clockwise around the downpipe and try to remove it through the exhaust tunnel. With persistence, heat shield will come off.
10. Remove midpipe/catback
Now that the heat shield is out, start by removing the downpipe bolt which is attached to the catback. If you have aftermarket catback, just remove the midpipe and set it aside. If you have the stock catback, remove the rear brace and just push the catback back to free some room.
11. Remove downpipe bolt
There are 3 10mm bolts that are holding the downpipe to the turbo. You can reach 2 from the bottom and 1 from the top. It is possible to remove all three from the bottom but it's quite difficult. Be sure to use plenty of penetrating fluid to ease the process.
23. Remove the downpipe
This is the HARDEST step of the tutorial. There are many ways to remove the downpipe but I used COBB's method and decided to remove it from the bottom. Once all the bolts are removed and catback out of the way, the downpipe should be free. Try rotating and wiggling the downpipe through the tunnel and with enough persistence, it should come out. Once the downpipe is out, pat yourself in the back because it's all downhill from here.
24. Swap the gasket ring
Before putting the new downpipe in, you need to swap the ring gasket from the factory downpipe to your new one. This can be easily done using flat head screwdriver.
25. Install the new downpipe
Whether your new downpipe is catless or catted, it should considerably skinnier than the stock downpipe. Just feed the downpipe through and install the 3 bolts.
26. Install back everything
Just repeat the step backward: Install 2 o2 sensors, bolt up the manifold heat shield, reinstall the catback, intake, cowl, headlights. Don't forget to reflash the map to stage 3 or you'll have to deal with the CEL.
Enjoy your new downpipe!
Tools needed
1. 8mm, 10mm, 12mm, 14mm, and 15mm socket wrench, combination wrench, and ratcheting wrench (HIGHLY recommended)
2. Set of extensions, universal joint (recommended), and a breaker bar
3. Ramp or jack with jack stands
4. Penetrating fluid (i.e. PB Blaster or Liquid Wrench. NOT WD-40)
5. Set of 22mm O2 sensor wrench
6. Set of philips screwdrivers
7. Set of torx screwdrivers
8. Gloves and eye protections
1. Remove the Wipers and upper cowl
If you haven't already, pop the hood and let the car cool. You don't want to work on the exhaust when it's hot. Let it really cool and begin by removing the wipers. Remove the wipers by removing the rubber cap and the 15mm nuts underneath. Before removing the wipers, mark their location with a tape. If you have a dirty car like me, the marks will be quite visible without the tape. After the wipers are gone, remove the upper cowl by removing clips using flat head screwdriver. After all the clips are gone, just pry the cowl with your hands.
2. Remove the headlights
Now it's time to remove the headlights so we can reach the lower cowl. Start by removing 2 torx screws and 1 screw push tab. Once the screws are out, pull the headlights up and you'll hear a loud noise. This is normal. Once the headlights are out, unplug the harness and set it aside. Repeat the same thing on the other side.
3. Remove the lower cowl
Once the headlights are out, remove 4 10mm bolts (2 on each side) that is holding the cowl in place. Once the bolts are removed, just pull it out then set it aside.
4. Remove the upper intake piping
Now, there should be plenty of room to work with the intake. You just need to remove the upper piping in order to have space. Start by loosening 1 worm clamps on each end with flat head screwdriver or 8mm wrench. Once the clamps are loose, remove the bracket that's holding the intake piping with 10mm and 14mm bolt. Don't forget to remove the breather hose in the back of the intake (not pictured), and remove the intake piping.
5. Remove the upper O2 sensor
You should have a clear view of the upper O2 sensor. Soak it with penetrating fluid then use a O2 socket wrench to remove. I did it by combining O2 socket, extensions, universal joint, and a breaker bar to break it lose. Remove the O2 sensor and set it aside.
6. Remove the heat shield bolts
Now the fun part. Start by removing the heat shield bolt on the exhaust manifold. They are all 8mm black bolts and 2 of them can be reached from top and other 2 from the bottom. Just remove the top 2 bolts for now using ratcheting wrench then set it aside.
Now remove bolts that's holding the downpipe heat shield. They are all 10mm silver bolts. 4 of them can be accessed from the top. There's one more bolt that can be accessed from under the car.
7. Remove lower O2 sensor
Now under the car, you can remove the lower O2 sensor using a socket wrench and O2 socket. Be sure to soak it with penetrating fluid before tackling it. Once it's removed, set it aside.
8. Remove downpipe bracket
While under the car, remove the bracket that's holding the downpipe which is attached to the rear motor mount. Remove 4 13mm nuts and the bracket should be free. Set it aside.
9. Remove downpipe heat shield
After removing the last 10mm bolt from under the car, downpipe heat shield should be free. This can be a bit tricky but it can be removed under the car. Start by rotating the heat shield clockwise around the downpipe and try to remove it through the exhaust tunnel. With persistence, heat shield will come off.
10. Remove midpipe/catback
Now that the heat shield is out, start by removing the downpipe bolt which is attached to the catback. If you have aftermarket catback, just remove the midpipe and set it aside. If you have the stock catback, remove the rear brace and just push the catback back to free some room.
11. Remove downpipe bolt
There are 3 10mm bolts that are holding the downpipe to the turbo. You can reach 2 from the bottom and 1 from the top. It is possible to remove all three from the bottom but it's quite difficult. Be sure to use plenty of penetrating fluid to ease the process.
23. Remove the downpipe
This is the HARDEST step of the tutorial. There are many ways to remove the downpipe but I used COBB's method and decided to remove it from the bottom. Once all the bolts are removed and catback out of the way, the downpipe should be free. Try rotating and wiggling the downpipe through the tunnel and with enough persistence, it should come out. Once the downpipe is out, pat yourself in the back because it's all downhill from here.
24. Swap the gasket ring
Before putting the new downpipe in, you need to swap the ring gasket from the factory downpipe to your new one. This can be easily done using flat head screwdriver.
25. Install the new downpipe
Whether your new downpipe is catless or catted, it should considerably skinnier than the stock downpipe. Just feed the downpipe through and install the 3 bolts.
26. Install back everything
Just repeat the step backward: Install 2 o2 sensors, bolt up the manifold heat shield, reinstall the catback, intake, cowl, headlights. Don't forget to reflash the map to stage 3 or you'll have to deal with the CEL.
Enjoy your new downpipe!
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