88 Bronco, 77K original, 300 I-6 EFI.

Car drove great. Nice and smooth. Failed NY emissions with high HC, and CO...exhaust is nearly new, cats look great no dents rust, nothing.

Replaced:
plugs, wires, cap, rotor, air cleaner, filter element in air cleaner, PCV, vaccuum lines new, injection cleaner used...

car ran great, check engine light still came on.

Check engine light on, Codes read, replaced O2 Sensor.

Light is now off, I started the truck up, and it idles like it wants to stall. when I am driving, it is strong and drives fine, as soon as I stop for a light, or put it in park, and it feels like it is going to stall. It revs up and down, and that is it. I had no trouble at all installing the O2 sensor, harness is tight, properly torqued etc.

Does the computer need some time to adjust to the new O2 sensor, or have I now caused something else to fail so quickly? I havent retested emissions yet since I need to get the car running right before I have to pay again.

I also used the "Guaranteed to Pass" treatment on a full tank, but still need to run the tank down low.

thanks, I am on a tight budget, and am doing all the work myself in the snow, so I appreciate all the help.

 

Did you disconnect the battery when you replaced the O2 sensor? That's something that's fairly easy to do and could do the trick. Disconnect it for about 5-10 minutes to make the computer re-learn operating parameters when reconnected.

 

Check your throttle cables. I had that issue once and it was throttle cables that had come partially unclipped and the vibration of the motor was causing the throttle plates to open and close a little bit, just enough to make the IAC go crazy trying to keep her running.


-=Whittey=-

 

My dad's F-250 would do that every time the battery was disconnected. It would have a real tough time idling and stall on and off but run great for about a week or so. Then once the computer gets its stuff back together it runs like a champ.

Wait for a day or two and see if it self corrects itself.

good luck

 

I did have the battery unplugged when I replaced the sensor, didnt want to damage anything. Now, then I ran the car for quite a while thinking it would correct. Parked it for 2 hours, then ran it again. Still idled poor. Now, this morning, it doesnt start at all!!!! All it does is keep cranking and cranking, and doesnt even come close to starting. I checkedc all grounds and wire connectors...not sure what to do now. Thanks