It cause the CEL to come on and put the PCM into open loop. But if the MAF is not pushing the proper data to the PCM, that definitely can cause it to run like crap.

 

well, I don't know why i quoted that as I am not answering it (swartlkk already did), but here is a sweet how too.
https://blazerforum.com/forum/showth...ighlight=clean

 

I had been looking for that thread! LOL

Moved to the Tech Article (DIY) section:
How-To: EGR Valve Cleaning

 

The check engine light is on regardless, and comes back on very two weeks or so becuase of O2 sensor problems. But the engine definitely runs much much better without the MAF plugged in, and I get better gas mileage now too. Its been a problem since I got it and I have never felt it run this well. I'll buy a new sensor and it should run even better than it is now.

 

Wow!
I have been having trouble for quite sometime with my Blazer experiencing really sluggish performance after starting when warm. I would step on the gas pedal and it wouldn't respond very well for a minute or two. I unplugged the MAF and all issues have gone away. I recently suspected the MAF was the problem and followed the tech article on cleaning, but I guess mine is defective. I didn't realize they actually went bad. Yes My CEL is now on, but the engine is running better than every. I guess it's time to replace the MAF.