Any Experience With These Fault Codes?

[infocusf8]

A few weeks ago I got a CEL on my '99 Boxster with 80K mi. and the following fault codes read out on the OBDII reader-P1124, P1126, P0130 and P0150. I took the car in and a smoke and liquid test was done to determine if any intake leaks were occurring and none were present. The MAF was removed and cleaned and I replaced the K&N filter with an OEM filter and the intake box was cleaned out. The codes were cleared and I drove for a few days and the CEL came back on again this time with the following codes-P1124, P1126, P0410 and P1411. The shop I use wants to do another smoke test and basically start at the front of the car and test all the way back. I'm starting to feel like this is another wild goose chase like the one I just went through trying to fix the gas gauge needle that ended up with me spending almost $500, replacing parts that turned out to not be defective and the gauge still doesn't read full when I fill the tank. Does anyone have any experience with these codes and what was done to solve the problem. I'm not interested in gas gauge fixes as I'm done spending money on it. Your help with what was done to fix the specific fault code problem (s) will save me several hundred dollars in another series of tests that may or may not solve the problem.