couple days ago i installed aftermarket plenum, while tightening the egr bolts the plenum cracked so i replaced the stock back on. no problem with the car running before i changed the plenum. now that i put the stock plenum back on the car is acting like its running out of gas at times, but not all the time. it will run like this for about 5 min., just sputtering and lunging like its not getting enough fuel. so far i have cleaned the iac, new gasket for iac, disconected battery, took plenum and tb off and cleaned those, re-tightened everything to spec., checked and double-checked all hoses. drove it today for about a fifteen min drive and it ran fine untill i was driving into my driveway and it started the same stuff. like i said before, the car ran fine before i had to change plenum and then change back. any suggestions