Ok, complete hypthetical but hoping to get an honest answer. What would be the negative effects, and time frame of such effects, if you were to drive a stock car around on a cpu tuned for stage 2 (turboback) on Ecutek? Anyone???

Was the tuned map tuned for the same intake and injectors that you're running now. If not, then I would not drive the car until that is resolved. The car will probably learn (via fuel trims) to idle reasonably well, and perhaps even drive around, but I wouldn't risk driving at more than a snail's pace, and I'd only do that after verifying (with a logger) that the fuel trim and AFR are both reasonable at idle. EDIT: and stay reasonable while driving.

If the fuel trim (AFR Learning A) is off by more than 10%, stop there. If it's within 10%, you're not necessarily doomed...

I'm guessing you'd be fine if you stay out of boost since stock and tuned maps are generally pretty similar in the idle and cruise areas. If it was my car, I'd take that risk, because I think the risk is very low, and because I trust myself to be super gentle with the throttle for as long as necessary. However I would not let a friend drive the car.

I'm also guessing you could floor it and still be fine (less confident about this, though) since you just wouldn't hit your boost targets due to the exhaust restrictions. So basically you'd be stuck on the lower-airflow regions of the maps. However I wouldn't personally want to test that.

I'm also assuming that the tuned map was using the stock boost control solenoid, or one that requires less wastegate duty cycle than stock. That way you'll get less boost than the tune calls for. If it was tuned with one that requires more WGDC, then you could end up with more boost than stock, but probably still less than the tune expected (again, due to restrictive exhaust). That might still be fairly safe but I'm not sure I'd risk it.

I'm sure others will be along to point out things I'm overlooking... :)

Thanks! Very helpful!