Reset Trouble Codes on 1999?

How do you reset or clear the trouble codes on a 1999. While cleaning my throttle body I needed to start the van without the mass air flow sensor connected. Now my check engine light is on. Can I reset by disconnecting the battery or do I need to have it put on a computer?

Thanks

I believe the only way to reset the computer is with a "code reader" or a scan tool. But on the other hand, your light should go out, after you drive the van a few times because the condition that cause the light to go on does not exsist anymore. So when computer detects the condition is not there anymore, after so many drive cycles, it should shut the light off, but the code will be stored.

GM OBD2 has to have 50 starts without ANY errors to clear the light. Now that being said, Autozone has the tools to check and clear these lights, but they will not clear them. You have to be VERY INSISTANT with them.:banghead: I have a venture and needed the light cleared after I changed the intake manifold gaskets. I had to tell the guy, "Look, I am the ONLY person who will EVER wrench on any of my vehicles, so either you will clear this light or I will find another auto parts supplier." Even after I told him this we had to wait untill there was no one in the store and no one outside, because he was afraid that someone would see him press that horrible "CLEAR" button.

I disconnected the battery and started the van. That didn't do it, the light was still on. I checked in the fuse box and there was a jumper. I believe it was marked diode on the cover. I removed it for 1 min. Started the van and the light was off. Not sure if that did it but the light is off. I drove the van around for a while, it's running great. The idle is much smoother now.