CEL & OBDII Reader

[Alan 01 Boxster S]

Last week I got a CEL for the first time and dropped by the local autoparts store to borrow their OBDII Reader. I could get no reading, it said that the unit was not connected. I used a standard OBDII connector which fit the port. Over the weekend (I couldn't resist) I "got on it" and the CEL went away.

Here are my questions:

1. Any idea why I couldn't get a reading? The reader was an AutoXRay, I believe a quality instrument. Anything funky about the Porsche OBD protocol? Suggestions? The fault is gone now but I want to read (and clear) my faults as part of my 45k service. (Owned the Boxster for almost a year now, plan on doing my first service at 45k miles, 43k currently.)

2. I plan on purchasing an OBDII reader. Any recommendations for home mechanic use?

[geoff]

I had the same experience with my '01 right around Thanksgiving at 50K miles. I went to AutoZone, gave them a credit card deposit, and they loaned me one of their Actron OBD2 readers. It worked fine and said I had a P1130. I reset the code which turned off the light. When the CEL came back on a few tanks of gas later, I think I tracked it down to a mass air flow sensor, and repeated the AutoZone process and haven't had my CEL back

If you do a search here on Durametric, you'll find a lot of comments on their Porsche specific diagnostic tool which does a lot more than the generic OBD2 readers. I plan on getting one the next time I have a check engine light