DO NOT remove the SAP system and try to work around the problem. You will be sorry if you go this route.
Resolving the problem is not a difficult as you may think. You may have 2 problems. Could be a lazy pre-Cat O2 sensor, could be a vacuum leak. Could be both.
A lazy pre-cat O2 sensor will not trigger Lean codes, but can cause SAP codes. Other problems can also cause SAP codes.
So start reading and starting thinking before you jump on anything. DO NOT replace sensors as your first order of business. Pre-cat O2 sensor replacement may be due anyway. They are consumable and should be replaced every 100k or if there are codes for the sensors before then. Since O2 sensors have been used, I typically only see O2 sensor heater codes, I rarely see codes for lazy O2 sensors, might be able to count on one hand the times I have seen an O2 sensor code for a sensor that is not reporting correctly.
Here is some light reading for you:
Readiness Monitors not clearing? - E46Fanatics
Emissions Readiness Help - E46Fanatics
P0411 solution for 330 with SAP MAF - E46Fanatics
Secondary air pump system P0491 and P0492 - E46Fanatics
Secondary Air Pump - E46Fanatics
Intake Manifold and Vacuum Caps - E46Fanatics
http://forum.e46fanatics.com/showthread.php?t=106959
Secondary Air Pump - E46Fanatics
http://forum.e46fanatics.com/showthread.php?t=106959
SAP (Air Pump) Simulator - E46Fanatics
Need to pass inspection, P0455 no CEL - E46Fanatics
Failed CA Smog for Secondary Air Injection Not Ready - Here's what I did! - E46Fanatics
Read my comments in this thread as well -
Help With Misfire & Engine Fault Codes - E46Fanatics