My 99 blazer was hesitating a lot an seemed to have significantly less power for a few weeks. Finally I got to opening up the hood and saw that my air intake duct had came off of the air box. Hence...causing it to suck in unfiltered air. I got it back on...it's better...but not back to normal. I still get fair amount of hesitation and don't have the take off that I used to. I suspecting the Mass Air Flow Sensor, but at over $100 for one, I thought I'd ask around here before playing the swap game. Any ideas???

Thanks...

ADDITION: This Blazer was tuned up last september with new plugs, cap, and rotor.

You can clean the MAF using MAF Cleaner or a brake cleaner, just be careful and use a soft brush and try not to break the elements

Thanks...

I got some MAF Sensor Cleaner...pulled off the sensor (I could see gunk on the sensors)...gave it a spray...let it sit for about 45 minutes...started it up...took off...and it was pretty well back to normal. $6 for cleaner is a bit cheaper than $100-$150 for a new sensor.

Awesome glad I could help. You also may want to clean the throttle body too