This may be a stupid question, but how can I be sure this thing is locking up? Would I be able to drive almost normally without it? I just figured my gas mileage (12mpg combined with a granny foot) and I was expecting slightly higher and I'm wondering if this could cause me that problem.

 

I know I had to un plug it from my stock trannyto get the car to pass emissions. The car stil drove normal but the TCC enabled the car so the convertor wouldnt lock up at low speeds.

 

Drive down a level road(or slightly uphill) at about 50-55 mph. While cruising smoothly with light throttle pressure, and maintaining speed, squeeze the brake pedal. Not enough to slow the car down, but enough to put the brake lights on. You should hear the rpms climb 200-300 rpm. When you release the the brake pedal, it should drop the rpm's back down. If you hear this, the lock up is working. No change in rpm means time to start looking for the problem.

 

if it is locking up and you are driving around 55 to 60, and let go of the gas, what should it feel like