Resetting ECU after header install

So I just finished installing my LCE header on my 2.7 this afternoon and I have been reading mixed things on other websites on whether or not to reset the ECU to relearn its parameters with the new header. I thought I should ask my fellow TW members if I should reset or not. Will the computer eventually learn or does it have to be rebooted. Thanks for all your help in advance!

 

It wont hurt, just do it.

Though to get technical, your engine is going to have less back pressure, this will affect the rate that gasses transit though the engine, which will affect the fuel injection timing as well as EGR operation. So yes, i would reset it.

Which headers did you install? Pics?

 

Do this by disconnecting the negative battery terminal? Also hoe long will it take to relearn? I do mostly in town driving rarely going on the freeway.

 

If resetting it had negative risks, was time consuming or difficult I'd understand the need for consulting. Just do it

 

I put an LCE on, Ill post pics later!

 

Don't worry about it. Your not going to tell the difference while the ecu is "relearning". I don't think it takes that long, couple of days maybe?

 

No need

 

Just a couple pics after everything is installed and the intake is in the way, forgot to take pics while I was putting the header in. I notice a big difference in power and sound though!

 

it's best to ask someone with an obd2 scanner to clear your ECU. the ECU has a backup battery inside that saves everything regardless of whether the battery is connected or not. also, it could take weeks to re-learn everything, so +1 to reset ecu. however, relearning uses a lot of gas, about a 3mpg drop while it does it's initial checkup after a reset, so -1 reset. up to you, you'll probably save more gas just letting it do it's thing w/out resetting.

 

Where are these assumptions on the ECU taking weeks to relearn coming from???? You are all reading way too much into this, its not calculating flight for a ballistic missile, its just selecting numbers on a pre set fuel map.

There are only three things that are saved on the ECU with battery off. OBD Monitors, and long term fuel mapping.

If your engine is running efficiently, within parameters for efficient combustion, the long term fuel trim will not have to adjust much from baseline, within a handful of drive cycles it should be fully adjusted.

Your OBD monitors will all ready themselves within 2 to 3 drive cycles. Or a trip to the post office, then to the supermarket before heading home.

 

my assumptions come from 10+ years experience as an auto specialist along with watching the LTFT and STFT on my own vehicles scanner for weeks after repairing a major intake leak that was present for months (from the previous owner and a bad brake booster). my air/fuel mix didn't stabilize to stoichiometric til weeks after the repair. the vacuum leaks caused 15% rich situations to my computer and it took weeks to get it back to +/- 3.5% LTFT.

the matrix used by the system for the LTFT takes into account temperature, load, and rpm and another factor or 2 i think. so when you run your vehicle in the summer time, you won't be allowing the computer to diagnose wintertime conditions/temperatures. therefore it takes a while to fully adjust IF the computer has been running improperly for long enough. granted the differences will be minimal, those are still the processes by which the ECU runs.

so for the OP and his vehicle to have to relearn the previous year's worth of normal driving before the headers, it could take up to a full 6 months to relearn every temperature the vehicle has to encounter

If anything, it could just be said that the differences are trivial enough to not worry about. which is why ultimately I said not to bother with resetting since he's going to waste more on gas

 

Obviously it was a minor and/or intermittent leak, as anything more substantial would have caused a faster STFT rise to 12, 15, or whatever the trigger point is for a 1 point LTFT increase on these systems. The o2 is going to be the main input to adjust trim. Load and temp is irrelevant, as they affect STFT only at preset corresponding RPM values. Keep it in any constant edition, and it will affect LTFT, but unless you live on a mountain and work in a valley, all out cars spend a majority of their time coasting and minimal load.

Again, reading way to much into this. What no one is saying that after enough time, it wont make a difference in fuel mapping whether you reset it or not.