Ok, here's the deal. My '94 1500 'burb won't pass emissions due to high hydro carbons. The CO content was also high, but within the limits (barely). I was told that this typically means that the engine is running too rich. One of the things that I've taken a look at is the ignition timing. The sticker under the hood says 0 degrees BDC, is this right? I've come across other threads on here that have quoted anywhere from 4 degrees to 8 degrees. At any rate, when I went to check my timing, the mark is so far advanced that it's off the indicator markings on the timing plate. Does ignition advance cause an engine to run rich? Could this be the source of my headache? TIA.