The MR2 and All Trac Turbo use knock sensors to sense detonation. When detonation is detected, the ECU will retard timing and/or cut boost by engaging the turbo VSV - which is great, because it gives a nice safety net if we go a little too extreme with our modifications. The problem is that the stock Toyota knock sensors are very fragile. One good knock caused by excessive load, bad gas, or a backfire can kill it instantly. While it is better to kill the sensor than your engine, a new Toyota knock sensor lists for $154.47.
ATS discovered that a Chevrolet knock sensor could be used in place of the stock Toyota one. The ECU approves and everything functions normally. Chevrolet knock sensors are much more durable and far more economical. However, the fitting on the Chevrolet knock sensor is much larger than the hole in the Toyota block, so ATS made an adapter with the correct threads to install in the stock original location.
We have also sourced a pigtail with the proper plastic weatherproof connector for the GM sensor. Splice this into your harness and the GM sensor becomes plug and play!