Pesky check engine light!!
 

More codes... p1128 and p1130. Just did an oil change. Researched and found out if the filler cap is not tight these codes appear and will trip the light! So be careful when doing an oil change. Clean the gasket, tighten the cap well my friends....
1999 Boxster base with 128k miles.

Well, that's a new-to-me reason those codes throw a CE light!

These are oxygen sensor codes. Sometimes, the MAF is fouled or going out and the computer won't tell you it's going out but will tell you something is awry with the O2 sensors. Or, an O2 sensor has gone out and it will tell you the MAF is bad.

When it comes to emissions, the diagnostic codes on Porsches are not that accurate in my opinion.

If you know your Boxster has never had all four O2 sensors replaced, it's a smart thing to budget for and do sooner than later. When I replaced mine after 90k miles (all four mind you) I got a lot more power and far better fuel economy. You don't want to replace just one or one bank...

Not really. In the factory OBD II diagnostics manual, the first item listed under these codes are a vacuum leak, which was exactly what he had.

Well, generically speaking it's a "gasket," but technically it's an o-ring and you can inexpensively replace it separately. It's by design not a matter of tighten tighter, as you just turn the cap until it hits the stop..

While you're at it, replace the o-ring on the dipstick, too ... 'cause it's the same vacuum leak.

JFP, I guess I need to update my error code list!

Or what I should have said was that I have had codes produced for a failing MAF and it was a failing O2 sensor in reality.

There are multiple things that can tip the codes, a vacuum leak is the most common and probably why they listed it first.