10lbs Backpressure Too Much on S/Ced 3.4?

Posted this over in the performance and tuning section but see I should have posted it here. At full throttle I am getting 10+ psi of back pressure at the front O2 sensor. I know this is way too much for a N/A truck but how about a supercharged one? Any help would be greatly appreciated!

 

I would say so, I would assume you may have a clogged catalytic converter.

How many miles and does it feel sluggish, or has it started to feel like its loosing power?

 

100k. Ya, I have been chasing a power lose issue for months and about $1500 in parts and labor. Wrote the complete story in the performance and tuning section. No significant back pressure on a lift, only under load while driving. No CEL. 2 muffler shops said my exhaust is fine. Independent mechanic says no based on same data I got while driving.

 

Nice truck BTW! What are you riding in your avatar?