Hello..

Yesterday my battery just went south and The car Died on me running..I replaced my battery but know my car is acting weird on idle..Mostly when the A/C is on the car hunts for idle then it goes stable..

I have a Power FC..Did my Tune just got lost or what?

My tuner said that I should use the car so this way it should learn again all the sensors

any help?

 

your tune doesn't get lost if your battery dies

most evos struggle at idle with the a/c on

 

if ur tune is off and ur fuel trims are horrible then it will re-learn them and fix ur tune for you itself. to an extent. when the battery is disconnected you will loose ur fuel trim adapts

 

thanks for the response..the car was idling HORRIBLE when I installed th battery...When I turn the A/C on the car almost stalled and the a/c compressor was going in/out intermitent..After a couple of drives the car is starting to work fine..Ill check out later...thanks

 

yeah your ecu needs to read everything again i had that problem
drove it for like 70 miles and it went away

 

goodluck on everything you should be fine now

 

I know the 02-03 Lexus ES300's ran like crap after the battery went dead or when being changed. You have to like stomp on the gas just to keep it running for at least 10-15 mins. Then drive it like you stole it to get the ECU to relearn itself.

 

yea almost all cars when you disconnect the battery for long periods of time or even short periods of time, you'll need to start the car and just leave it sitting for about 10-15 minutes or until the fan comes on for the ecu to relearn the idle. you really arent suppose to be gassing the car, just let it sit on idle. its called the idle relearn process and was in the TSBs