Use a thermal probe or a infared thermal gun and measure

1. temps at each exhaust primary pipe
2. incoming to both CATs
3. Right after the CATs
4. in the muffler tips

See if all points left/right are about the same temp at each test point

I suspect at each primary about 300-500 degrees depending on exhaust manifold or header used

About 800 plus going into CATs
About 170 degrees in the muffler tips

I doubt MAP itself is an issue UNLESS oil got sucked into it
At idle should be about 35 KPA and of course if at sealevel with boost should hit 104 KPA at WOT.