I recently had my MAF and EGR valve replaced on my 01 blazer 4.3 because before the car ran kinda funny. it didn't idle rough, but it would hick up if i stepped on the gas a little too much. now with the new sensor and valve the hesitation has appeared to have stopped but it does catch me by suprise every once and a while at a red light and on top of that now my blazer idles rough which again, it did not before. i just wanted to know if this was normal seeing as how they are new parts or if i should just hunt down my mechanic and see what the deal is.

 

I believe in cause/effect connections. Did whoever replaced the EGR install a new screened gasket?
Every time you open that passage up you're going to stir up various and sundrie bits and pieces of carbon deposit.

 

im not sure if he did, i never talked to him after he did the work because he wasn't working today when i picked it up.