some idle problem causing stalling

hey guys i got a 3.4 alero 99 that i recently brought to build it up but im having a weird problem that i could use some help maybe someone got a similar problem ... anyway

when i start my car (engine Cold) it start normally and evrything but when i park with engine warm (normal temperature) my idle start to go wild and wilder then bang stalling then i can start it again but unless i give it some gaz it stall again.. considering that i brought it recently i changed plugs,wires,checked all coil pack then i checked IAC, MAF , cleaned the intake, now gonan check on egr i also found some vacum leak fixed em but stilll ... but i got MIL Light on its P0134 p0135 and its no activity in the primary o2 sensor but i dont think that it im not sure yet i have a brand new o2 to install but well winter.. anyway by the time i get a place to do the job im still tryng to find out what it is cause i dont think o2 would cause that anyway oh and my powersteering pump is in need to be changed but nothing urgent..

anyway guys thanks for reading this and giving me some tip if u are thanks in advance :) :uhoh: :grinyes:

The front O2 sensor can be changed in less than 30 minutes easy in your driveway. I have done it. The wiring for the O2 sensor is pretty close to the hot exhaust, maybe that's why you have no activity. Fix the known problem with the O2 circuit, then try to chase down the idle problem. I'd guess a new O2 sensor will solve your problem.

thanks il try that but the o2 i tryed i need to warm it with torch anyway im gonna do it and we will see but i know its not the wire cause with the scan i see 600mV comming from the secondary but only aroun 60mV from the primary so i guess the o2 is dirty or something

I would also inspect the wires going to the MAF as they can get damaged and it will cause you some irratic idling.

ALso when you replaced the IAC, did you calibrate the tip to its proper length ?

yeah i did ajust the iac im gonna look up the wire but i did it the quick way (checking MAF data on scan while shaking wire) but seemed ok im gonna change the o2 this week-end we will see from there thanks Xero