I've been running with a slight air leak for a while, when I repaired the leak the car would idle rough. I've now done about 100 miles with the rough idle and it's been getting better with each mile to the point that its nearly back to normal.

My question is, did the ECU recognise the leak and change the fuel/air mixture accordingly and with it repaired has it had to relearn the correct mixture??

 

Bump, if i'm talking out my **** at least let me know

 

The ecu will continuously monitor the readings from the lambda probe in the exhaust and adjust the fuel according to the oxygen content in the gas stream. its called air fuel ratio correction. it will slowly work its way back to as near as 0% correction value as it can possibly do. You should really once the leak had been fixed reset the ecu manually so it starts learning from scratch again rather than wait for it to sort itself out

 

Thanks for the response, how do you reset the ECU manually?

 

Disconnect the battery for a while will reset it.
Jay

 

Ahh, thanks for that.

So would this explain why some people have problems when fitting things like Dump Valves?

Thanks again.