I checked mine just for kicks. I did a speed test on EDGE and it was 265.8kbps, turned wifi on and went 2474.2 kbps. All download speed ofcourse. If T-Mobile would get the 3G towers up in columbus, maybe I can test that too then.
If we lived in Europe I'd tell you to get one of these:
FAPFAPFAPFAPFAP
http://jtmedia.kuvat.fi/kuvat/LOWR1D3Rpt.III/JAP-3/IMG_2064copy.jpg/_small.jpg
http://jtmedia.kuvat.fi/kuvat/LOWR1D3Rpt.III/Q-fun/IMG_1082copy.jpg/_small.jpg
Mine says OK and I have a check engine light on for secondary O2's and my ABS light was on because I had a bad ABS sensor. OK wont come one when brake fluid is low I've noticed. I think the same for washer fluid.
Heres another
http://elektro.cmhnet.org/~graydon/exhaust.html
http://elektro.cmhnet.org/~graydon/4-rings.jpg
http://elektro.cmhnet.org/~graydon/Exhrear.jpg