2005 4.0 V6 loss of power

Hey guys, I don't post on here much, but I have recently encountered a problem which I cannot make heads or tails of and was looking for a little direction.

Recently my 2005 4.0 V6 6spd has experienced quite a loss in power when trying to accelerate.

A few things about the truck:
171xxx KMS
Recently changed oil and overfilled putting roughly 5.5L instead of 5.5qt and drove roughly 200KMS before I drained to correct level.

Only run supreme fuel.
Has Spectre cold air intake.
Cat Below efficiency(Bank 2) code showing.
Recently Seafoamed engine.
Truck seems to idle fine.

Been looking thru threads and don't know which direction to start in. Any input would be greatly appreciated!

 

Seafoam? Hmm, read that it can cause cat problems. Only read, just what my dumb ass has learned on the 'Internets'.

 

I would definitely start with the problem causing the check engine light.

 

Thanks guys. Do you happen to know how I would go about checking or cleaning out the Cats?

 

They can only be replaced.

Rapping on it to see if it rattles is a good starting point. If it's disintegrated inside it can both set the code you have and partially block the exhaust stream, allowing idle but causing your power loss.

One quick check is to open the exhaust ahead of the converter (assuming that's possible on these, not sure the position of the converter in the exhaust?) and see how it runs then (besides being noisy). If it free revs and runs ok, good chance the converter is clogged.

 

I went underneath and took a quick look and it looks like I have 4 catalytic converters, two of which are connected directly to my manifolds... So it's looking like a possible header job...