Reach under the dash. Spin the Pulsar dial to (Heavy Tow/Max Power).

Reconnect the batteries. Do not start the engine yet.

First, pop the hood. Locate the negative terminal on the passenger-side battery. Pull it. Now walk to the driver's side. Pull that negative terminal, too. The L5P has two batteries; if you leave one connected, you risk a voltage spike that will fry the Pulsar before it ever sees a map sensor. Wait five minutes. Let the capacitors in the ECM drain. You’ll hear a faint click from the fuse box. That’s the signal.

But for the 30 minutes it took to install, and the $1,200 it cost, you’ve done what GM engineers wanted to do before the lawyers stopped them. You’ve let the L5P breathe.

You’ve lived with the 2017-2019 L5P long enough to know its dual personality. On one hand, it’s GM’s masterpiece—a 445-horsepower, 910 lb-ft torque monster with a robust rotating assembly. On the other, it’s strangled by the EPA’s digital leash: torque management pulling fuel during shifts, a 98-mph governor, and throttle lag that makes a freight train feel like a sports car.

The Prelude