New intake, question

[fastplant]

A friend of mine told me that now that I have a new intake in the car I should disconnect the battery for 30 minutes then reconnect it and start the car and let it run for a bit. This is supposed to reset the o2 sensor to the new intake and make it run better. Anyone else hear of this, should I do it, doesn't seem like it could hurt.

[CleanGS97]

what he's trying to get you to do is clear the ECU's fuel curves. Your ECU is programmed to "learn" your car's fuel and intake settings and optimize them for how your car is configured. Since you changed the intake you are going to be getting more air than before so it would be a good idea to clear the fuel-curves and let the ECU re-learn them with your new setup.

-Aaron

[Rogue_Ant]

Your ECU will learn what is best if you drive it around for a while or disconnect the battery.
Disconnecting the battery will 'force' the ECU to learn faster though, since it is essentialy learning everything (again).

Rogue

[Blackboost]

Originally posted by Rogue_Ant
Your ECU will learn what is best if you drive it around for a while or disconnect the battery.
Disconnecting the battery will 'force' the ECU to learn faster though, since it is essentialy learning everything (again).

Rogue

I differ from this. I believe that the ECU will take longer to learn the engine if you disconnect the battery and reset it. The ECU was programmed to get to know the engine and change itself (a little) when she sees some changes on the engine. The thing is that she's even more slower if she is reset...

[nano]

I thought the N/A engines had no knock sensor. And I also thought the ECU ran closed looop at WOT (or what ever it's called), when the ecu stops monitoring O2 voltage. Therefore the only thing the ECU can monitor is air flow. So wether you reset the ecu or not I don't see how's it's going to change the fuel trim. It's going to add a certain amount of fuel depnding on airflow, and probably has built in maps for timming, but it probably also relates to the amount of air flow coming in.

I know that on my car when I encrease boost (encrease airflow) the ECU has no problem isntantly compensating. When I add race gas it only takes a few seconds for the ECU to maximize it's timming, but timming is only maxiimized on an engine with a knock sensor as far as I know. I've also been to the track and literaly on the first run with race gas the car is already running at it's peak. Then I reset the ECU to see if it changes my times and they don't, they're exactly the same.

As far as I can tell the only thing the ECU learns is how to reach it's optimal A/F at idle and anywhere at part throtle. Basicaly everywhere where the ECU is running in open loop. Therefore not affecting WOT performance. I hope I got that open loop, closed loop thing right. I always get those two mixed up. Just my observation though.

[Rogue_Ant]

Blackboost, now that I think about this your probebly correct as the ECU only needs to change a small amount but resetting it forces it to go through the 'learning' cycle completely.

Nano, you are correct in his statement although you got the terminology wrong. Closed loop is when the ECU is receiving feedback from the O2 sensor. Open loop is when it ignores the O2 and reads from a preset table.

Rogue

[fastplant]

Thank you, actually, I've noticed that in the past few days it's finally realizing more air is coming in. I think it's already reset. I'll just leave it as is, thanks again

[Rogue_Ant]

No problem.

Rogue