MAF Sensor
 

Thanks to everybody who helped with my coolant issue. It's fixed.

Now my engine is running poorly. Fluids are good. I've read a lot of threads and have decided to check the MAF sensor as well as vacuum lines.

So, I did what was suggested to see if the MAF was bad. I unplugged it, and immediately the engine started running smooth. However, the engine continuously revved higher and higher. Is that normal behavior?

Check your IAC?

I believe when a critical sensor "goes" the PCM runs the engine using different values.

Have you cleaned your MAF sensor yet?

You say it revved higher and higher? If it just went up and stayed there, you may have unplugged the throttle position sensor. I had a similar experience a couple weeks back.

If you're positive it was the MAF, then it was probably just your engine running off of simulated data rather than actual sensor readings. Check your vacuum lines, IAC, throttle plate, etc.