I have had a rough idol only when the engine gets warm, cold starts are hard most of the time, the Idol issue is only when breaking or stopped, I have a new EGR valve ( a year old or so) and I put a new gasket on it and it didnt help. So would it be the Plenum seal, spider injector or fuel pressure regulator? I also have CEL p1134 but I dont have a tail pipe and my muffler has a hole so i think its a back pressure issue.

Any help is appropriated thanks

95 s10 260k 4.3L 4x4

 

When braking or stopped, when you are stopped, is your foot on the brake pedal, or is it present in park with your foot off the break as well.
If its only when your foot is on the break, I would suspect a vac leak

 

The rough idol is always resent, slightly less when in park gear, where might the leak be do you think?

 

I would start by checking the big vac line coming off the brake booster going to the intake