2005 Scion TC

Tune it Power is everything

Pros
The factory header system utilizes a built-in primary catalytic converter. Using the Alphawerks header eliminates this catalytic, leaving you with the secondary cat, which is still attached to the factory b-pipe. A gain of 8hp was achieved from 5700rpm to redline and 7 ft-lb of torque improvement was recorded at 3300rpm and once again at 5600rpm, which stayed constant until redline.

Cons
Removing the factory heat shield to access the factory O2 sensor proved to be a bitch. We notched the heat shield where the factory bolt protruded to easily remove the cover and gain access to the O2.

Notes
Alphawerks provides a detailed schematic on how to install the O2 simulator which is sold for $50 dollars. The three-wire black box is tied into the factory ECU and tricks the factory ECU while eliminating the dreaded engine check light. In less than 15 minutes, we used two butt connectors and a t-splice to connect the wires. We reset the factory ECU by disconnecting the battery for two minutes. The O2 simulator worked like a charm and the engine light never once reared its ugly head.

Installation time
50 minutes

Tools
12- and 14- combination wrench, 12- and 14- socket, ratchet, extension, screwdriver

Temperature
77.6 degrees Fahrenheit
Temperature difference from previous run: +1.5 degrees Fahrenheit

Parts
Header, O2 simulator, instructions

Conclusion
Using three simple to bolt-on power adders we were able to gain 15.1 wheel hp and 7.9 lb-ft of torque to the 2.4-liter Scion. This was an impressive gain when considering how difficult it is for most OBDII vehicles to produce ponies without the air of a forced induction kit or internal engine work.

Tune it Power is everything