I replaced my EGR valve because previous owner put a block-off plate there instead of fixing the problem. Now, car starts well, idles really smooth and have a good throttle response off idle, but it lacks power when in gear. As soon as you take off, it feels like it wants to die.

What could have someone achieved by blocking the EGR passages? Can you cheat another problem with that trick?

It would run pretty well with the block off plate, it was just shaky when hot. Now it doesn't shake but it misfires a bit and feels like it wants to die get going from a stop.

Car is 91 Cadillac brougham d'Élégance with a 5.7L

Check it over for any vacuum leaks.

Carb cleaner?

That'* what I use.

thanks, I'll definetly try it

I checked and checked and rechecked again, there'* no vacuum leak.

I've checked the controller. The car runs super fine when it'* unplugged. I checked the voltage, there a constant 12V in the connector pins. Is it normal? I'd think not. If not, what causes this? Grounded ECU connection?