2002 Oldsmobile Alero 3.4L V6My car runs exremely rough on cold start ups(not nessesarily on cold days but just after it hasnt been running for awhile, but cold days make it worse) but after a couple minutes of coughing and sputtering it will rev up to about 1600-1700 rpm, then settle back down to idle and run perfectly until i shut it off and the engine cools down alot. i have replaced the spark plugs and wires, installed a k&n air filter and a new pcv valve. Fault codes are all to do with O2 and HO2S sensors but I thought these didnt affect startup idle while the system is in open loop before the O2 sensors heat up so does it make sense that its a faulty O2 sensor causing my rough startup? the fault codes i pulled are as follows:
#1: HO2S/O2S Insufficient Switching Sensor 1 Or Bank 1 Sensor 1
#2: HO2S-11 (Bank 1 Sensor 1) Circuit Low Input
#3: O2 Circuit Slow Response (Bank 1, Sensor 1
Try coolant temperature sensor
Try cleaning mass air flow sensor, jus use some maf cleaner and let dried. just don't touch the wires. o2 can cause a problem on cold starts since its a heated o2 meaning once its started should get up to operating temp quickly but since it might not be warming up as it should and once the engine warms up it kinda drive normal its it up to temp.
2,126 views
Usually answered in minutes!
×