questions on O2 Sensors

I have a 2002 z-28 and i am getting codes PO420,PO430 and P1153. I have the GM service manuals so i know what the codes actually are.
The problem is the PO420(bank 1 sensor) and PO430(bank 2 sensor) are codes relating to the 02 sensors. Something about an insufficiency in the system. I just installed all new oxygen sensors(four of them) and the catalytic converters are brand new SLP units.
The p1153 is for air leaks in the exhaust system or bad gas. I know for sure its air leaks cause i can hear them.
Could the 1153 code be causing the other codes to show up?
Should i be concerned? The car runs fine and gets great MPG's. The SES light is just really annoying.  

Get the exhaust welded solid then run the code reader again  

air leaks into the exhaust system dilute the exhaust stream so it throws off the fuel ratio calibrations....  

air leaks can come from
cracked exhaust manifolds...
loose exhaust manifold bolts..
blown out exhaust manifold gaskets.

now the hard to find air leaks..

rotted out air injection check valves. (the body actually is corroded away from the inside)
rotted out air injection tube manifolds..   (corrosive exhaust gasses eats away the tube from the inside)
burned out air injection check valves.   ( the check valve reed valve actually breaks off..  )

this is usually do to restricted exhaust system at the converter..

the worst one.. and is usually found after you have replaced the others...   the air injection diverter valve fails to function anymore..    

on computer controlled cars... there is usually 2 systems..  and upstream air injection..  this goes to tubes into the exhaust manifolds or into the back of the heads...   there is also a down stream air injection system.. this is hooked to the side of the exhaust pipe just in front of the cat or into the side of the cat...

the trick..    test the upstream hoses for airflow while the engine is running at idle...

most of the time.. they should only have airflow at idle for the first 30 seconds or so...   then they should shut off..

there are times when the ecm calls for upstream air...     slowing down , down shifting with your foot off the gas and the engine is still at speed....       any WOT operation when the computer drops out of closed loop...  and runs on pre programmed fuel control..  part throttle acceleration when  it passes a predetermined percentage of throttle opening and load....


i will try to add to this later... if you have more questions.. do post them...  

The air injection pump pumps air straight into the headers and are not connected to the catalytic converters at all on a 2002 Camaro. The stock system was this way as well. The system is completly aftermarket. It has SLP headers with a Corsa cat-back system. The car has 50k miles and is stored in a heated garage for 6 months of the year since we have harsh winters in Wisconsin.  

block off the air injection hoses into the headers...  prevent any air leaks into the tubes..   clear the codes.. drive the car and see if they reset...

this is just for a test.. ...  

Any idea what inefficient switching means? Thats one of the codes thats coming up. Bank2 sensor 2 inefficient switching(bad sensor). Also the other ones are, po420,430 are, catalyst system not working efficiently