'I have a 1994 Fleetwood Brougham and I have a popping sound whenever I turn my wheel and I can also feel it in my gas pedal. Can you please help me diagnos this problem. And I 've recently had my rear end changed. It happens when I'm turning corners and easing on the gas. At times I can also feel the popping in the gas pedal when I'm riding down the freeway.

Air in the power steering system? Try changing the fluid; then, turn the steering wheel lock to lock, to purge all air. Check out the power steering pump. Listen to it with a mechanic's stethoscope, to ensure the bearings are fine.

'I have a 1994 Fleetwood Brougham and I have a popping sound whenever I turn my wheel and I can also feel it in my gas pedal. Can you please help me diagnos this problem. And I 've recently had my rear end changed. It happens when I'm turning corners and easing on the gas. at times I can also feel the popping in the gas pedal when I'm riding down the freeway.

There could be more than one thing causing all of this. Someone is going to need to do some hands-on test driving to pin-point the symptoms and when they occure.
There could be something inadvertently left loose or under torqued in the rear end.
Could be worn or failed front suspension componentsor mounts. Or worn and/or failed motor mounts or trans mounts.
I've worked on Cadillac's for many years and there's lots of things to consider but you'll most likely need to find someone to help you locally.