check engine light codes can be found on this page. Bookmark it!
http://www.iwantaporsche.net/BoxsterCheckEngineLightCodes.htm
When your MAF goes or a O2 sensor goes out, it can throw a bunch of extraneous codes from what my mechanic showed me about my own car. I had one oxygen sensor out and he said the PST tool was showing the MAF not working either. We changed out the O2 sensor and voila! the MAF functioned perfectly and did not need replacement.
How many miles do you have on your boxster?