so , in drive it idles flat , in neutral or park it is hunting and not settling down. i had an o2 code and changed this out , the precat one . i have just completed a system reset and it is still the same.
it seems to drive ok most of the time ?? any ideas where to look ?
thanks !

i have just read it may take ten starts to relearn . ill see what happens

Try the Idle air control valve IAC, this could cause the motor to hunt. could have buildup on the pintle, when cleaning with brake or carb cleaner don't push or twist the pintle.

I was under the impression that it is working , because it hunts , it must be adjusting no ? And it idles flat in gear 🤷🏼‍♂️ but your right for ten mins I should just try ??

In park, some ECMs lower the amount of fuel the motor gets to save on the amount of fuel the motor burns at an idle in park. so for one count, the ECM gives more fuel while the next gives less fuel to keep the motor running, which is hunting. When the motor is under load, in gear or neutral, it gives the motor more fuel. You may want to hook up a vacuum gauge, there could be a vacuum leak. Gauge pressure, you should have about 18 to 20 inHG at an idle in park, if you don't, its time to get the smoke machine, or brake clean out to find the leak.

ok thanks

Updating , because it seems to have learned how to idle or not I'm not sure . Basically cold it sucks warm it's ok .

Updating , because it seems to have learned how to idle or not I'm not sure . Basically cold it sucks warm it's ok .

Try wiggling the wires/plug at the tps while it's running and see if it has an impact on idle.

Na pretty sure it's good , I'm suspecting the O2 heat circuit now, I've changed the pre cat O2 and it's the same , need to work out the heat circuit , maybe fused , bad connection, I'll keep looking .

Plug in a scanner and see what your short trem and long term fuel trims are. Should be at zero. -% shows less fuel +% shows more fuel if it's +% tool for exhaust leak, or vacuum leak if it's -% may have leaky injectors.

Thanks I will have to get access to something like that if I can't work this out .
so I learned today , as I keep driving it every day.
The out side temp is warmer . Engine cold , started and ran like a champ 💪 . Maybe it's not an engine cold issue maybe it's a ambient temp issue . Maybe intake air sensor or map 🤔

​​​​​Locate the coolant temp sender, right on the front of the motor by the upper radiator hose. Ground the sender wire and see if the motor idles better. When the engine is cold the computer adds too much fuel bacsically flooding it. When u ground the sending wire u bacsically tell the computer it a warm ening and will give it less fuel. If the motor runs better after grounding the wire you need to replace the coolant temp sender, only get Delphi, Delco, dorman. Don't get AutoZone/advance auto specials, even thoigh they are way cheaper they will not last blew through 3 AutoZone specials and said **** it I'll get the Delphi and it was quality had it in for over 2 years