Man last night I took the cat. converter out and changed the fuel filter it has a brand new fuel pump. plugs ,wires,just about everything and now not every time you pull off but some times it acts like its hesitating. went to the U pull it yesterday and found a MAF sencer, even though mine looks better I changed it what is it what am I going to do?

Last week It put the code out p0103 and this morning its p102. This all seemed to start when I triied to clean my old MAF sencer last week should I bite the gun and go buy a brand new one or what an thin if that dont work then what.

So with the original, the MAF output was TOO high in frequency.. that probably means it was 'noisy'.. {essentially acting like a microphone}
Now it's too low, which COULD mean it's really dirty.. or not working at all.

Try cleaning it. REMEMBER dont hit the sensor itself.

The sencer just so im clear is the black thing on the side?

ummm no.
Here is the proper method of cleaning the MAF
https://blazerforum.com/forum/tech-a...leaning-40420/

This is among many helpful articles to be found in the DIY index

https://blazerforum.com/forum/tech-a...93/#post213566
If people are serious about working on their own trucks, they should read each and every one of those articles.. at least to get familiar with their truck.