Weird. Torque clears P0420 on my car probably 1-5 times a day and you'd never know from the dash. I explained the gutted cat to one guy who test drove my car to potentially purchase, but he was still freaked out when the robot lady voice announced and cleared the fault code during his drive.

I'm betting that it's clearing the pending code, which doesn't light up the CEL.

In NJ all the systems have to be ready so this wouldn't work for me. So the only true option is to tune it out? I got excited when I read this and thought torque might work with passing inspection.:rofl:

Sorry for the newb question but what would an average shop charge to tune out a cat cel? Not tune the entire car, just block the code so it will fly through inspection.

Thanks fellas

Well, they would have to buy you an AccessPORT ($500) (or MazdaEdit), then download the free tuning software onto their computers, then probably charge you an hour or more to figure out where things are, then another 10 minutes to make the change and reflash your car.


There isn't a point in "having a shop do it", since there is literally nothing that they are doing that you can't do yourself with a few mouse clicks. You already have to buy an ECU flashing solution, and that will be paired to your car anyway. The software is free ... so why pay a shop to do all that?

ECUs aren't open and readable/changeable by any old shop with any old software. It takes specific firmware that is coded to read the ECU that is specific to that make and model of car, even that specific geographical version. And that firmware comes on a device that is locked to the car it's installed on. Uninstalling reverts to stock and removes any changes, so it isn't something that can be passed around to benefit multiple cars.