I have a 1995 Bonneville supercharged. I have for years now gotten a code stating the EGR valve was bad, I have replaced it twice and 1 control module and has made no difference. The car for some reason on a hard right turn, getting on the highway the car will die for a few seconds and then go.
Over the last 2-summers when the heat gets in the 90'* after I drive for about 30-minutes in this heat the car will start hesitating real bad, it is like it is not getting any gas. The only way to drive the car is to let it sit and cool down. I have been at the garage several times and they recently cleaned the throttle body but it still wants to die in hot weather although the car runs better on below 90 days, but now has a rough idle and still wont take acceleration when the engine gets hot and the outside temperature goes up in the 90'*.
I do hear a exhaust leak. I don't know if that would contribute to the problem.

*** Moved from Introductions ~ Kevin ***

Check your fuel pressure. You might be due for a filter change, pressure regulator valve change or a new fuel pump.

Give this article a read... it might not be it, but it almost seems like it might be the culprit.

https://www.gmforum.com/showthread.php?t=278980

The garage checked fuel pump and filter and they were good.

But did they check the fuel PRESSURE?

Yes, I have read something that a bad O2 sensor over time could have affected the catalytic converter and when it gets real hot the converter closes up and restricts flow.

You may have a fuel pickup or fuel tank baffle issue. I have the issue getting on the highway also, but only when the car has 3/8 of a tank of gas or less. Does the cutting out issue go away with a full tank of gas?

I am not sure of the surging however.

Yes if the tank is not low the hesitation does not happen. but the baffle I believe is part of the tank. Would I have to replace the whole tank.

I think the easiest way to confirm this issue, is by monitoring fuel pressures in real time driving conditions. This is rather hard though, because a fuel pressure gauge would need to be rigged in a safe manner, and be visible while driving. That is hard, but would absolutely tell you exactly what is going on. Also, the fuel pump is cooled by the fuel in the tank. The less fuel in the tank, the hotter it is outside, the hotter the fuel pump gets. I think a tank drop is in both of our futures. I also believe the baffles are an integral part of the tank, and replacement would be necessary if they are compromised.

Checking to see if a solution was found on this issue. My step-son is having the same problems on his 92bonneville. In the mornings he goes to work and the bonneville runs fine. When he gets off of work and its hot outside the car doesnt want to run. Said if he has to "work the gas pedal" to get it up to around 30mph. Thanks for any assistance.