The only code is 1451, which is a vent control valve. I plugged it back in, but code still registers.

When at a stop light the engine idles with an uh-uh-uh-uh, sort of a pulsating idle. When it's in park it sounds fine. Pulled codes: 1451. Looked under the bed and found the sensor unplugged, so I plugged it back in. The code didn't clear.Also I checked vacuum lines, found one and replaced...

I've heard good things about this forum and looking forward to exchanging ideas.