Toyota Matrix DIYs

This is the new DC Sports header (#THC-4405) for 03-05 Corolla. It fits all years’ Matrix/Vibe, XR or Base, perfectly and includes the O2 sensor bung that was missing on the first-design header. I bought the header from Petertracks (neverenoughauto.com) for $260.

Review: Installation took about 3-hours using basic handtools. No welding required. The header compliments well with the Magnaflow exhaust. I’m very pleased with the increase in acceleration, epecially in midrange from 2500-4000 rpm. With the stock header, whenever I punched the accelerator in 4th or 5th gear (no downshift), the engine would just be lugging against the weight of the vehicle without accelerating. Now, when pressing the gas I definitely feel a strong pull. The exhaust note sounds better – more of a performance “growl” than before, without being louder.

Here are some pics and install tips…

DC Sports header (#THC-4405)

Comparison between mega-restrictive, and ugly, stock header and DC header.

Collector views. Collector size is identical, even though stock header looks larger, because of exhaust soot.

Port views. Again, port size is identical, even though stock header looks larger because of exhaust soot.

Oxygen sensor was tight as a mo-fo! For leverage to loosen, I bolted stock header to a strut tower stud.

Installed view, from top. Use zipties to hold O2 harness away from header tube…

…or use 1/2″ Cool-Tube Extreme by DEI to protect O2 harness. Notice, Toyota uses these tubes to protect shifter cables from heat.

Installed view from bottom. Everything lined up perfectly!

Tools needed:
1) 10 mm socket – for engine cover.
2) 12 mm socket – for STB, heat shield & header flange bolts.
3) 14 mm socket – for exhaust pipe & bracket bolts.
4) O2 sensor socket or 7/8″ wrench – for O2 sensor.
5) 3/8″ & 1/2″ drive ratchets.
6) Various extensions.
7) Torque wrench.

Install Tips:
1. DC Sports’ instructions tell you to install header from underneath, after dropping midpipe from exhaust flange to axle flange. NOT NECESSARY! Leave midpipe in place and install header from top. It’s a tight fit – but with some twisting and wiggling, the header will install from the top. You’ll have to remove the engine cover and strut tower brace, first. Hopefully, you still have the stock strut tower “C” plates. You need to install them before raising the car off the ground, or else the front struts will fall out of the strut towers.

2. Use anti-seize on threads before installing O2 sensor onto header.

3. Carefully pry off collector donut gasket from stock header w/ flatblade screwdriver and gently tap into place on new header. A new donut gasket would cost $40!

4. Replace cylinder head exhaust gasket with new gasket. It’s difficult to replace if the old gasket were to start leaking. Tighten header bolts starting from the middle and working your way out. This will ensure even tightening and prevent leaks.

5. Use double zip-ties to hold O2 sensor wire harness away from hot header tubes. Zip-tie cable to brakeline running along firewall. Use double zip-ties, in case one were to break. Or, do what I did and use 1/2″ diameter Cool-Tube Extreme by DEI to protect the wire harness.

Since I had exhaust out of car, this was a good time to install my Energy Suspension mounts. Installation of rear mount is way easier when exhaust is out of car.