Please help me out here. Something weird started happening today (P0300) multiple cylinder misfires. And a P1133 which is something about the O2 heater circuit. Anyways, what is happening is at WOT my car runs fine, and at partial throttle it (Sometimes) decides to be a slug and bog, etc. Overall, it runs good, but it seems to be getting worse. The ONLY thing I can think is that I have an a/f gauge, and I had to tap into the O2 sensor heater circuit. For some reason my gauge decides to stop working sometimes, and when my gauge stops working, car acts up. Do you think that the gauge could somehow be grounded wrong and be shorting out the O2 sensor causing it to give wrong readings? Any info you wanna know ask away, and lemme know any ideas you may have. Thanks.

Well its either that or the O2 on the side you have the A/F guage wired into is bad. Pull your O2's and look.

how can I tell if an O2 is bad just by looking at it? Any ideas?

Its one of those obvious things. The tip will be black if it is fouled.

Hey, just unplugged battery, and reset code. So far so god. This doesn't eliminate possibility of bad sensor right? You think I'm in the clear? Or am I still gonna have to get under there and replace the sensor? I'm trying to avoid jacking car up, etc. to have to get under there to change a sensor. Thanks again.

I would unplug the guage from the sensor for a while and see if the problem goes away. That way you can rule out any interference from the guage. If the problem persists, check the wiring that you spliced into and then the sensor itself.