Down on power after reflash
 

Just about to have my ecu reflashed, is it true that you lose power and has anyone confirmed this on a dyno?

No one seems to know with any certainty...all we have so far are "seat of the pants" butt dyno impressions which have no data to back up the feelings...

Are you referring to the reflash that fixes the CEL issue?

I'll go on record and say I don't think this is true. I have a new ECU in my FR-S and it doesn't seem 'down on power'. Although it still does not idle well and seems to now have some kind of random throttle glitch or bog condition at low rpm.

Rob

I was also wondering about this. Will the new cars off production line with the new ECU be less responsive? Didn't someone on the forums say that they saw improvements after resetting their battery after getting the new ecu?

for the most part I think its the exact same before and aftrr'.... My issue is about 5% of the time I have a real bad bog and lack of acceleration down low from stop or almost stop...def no slow rolling start in 2nd gear......

:thumbdown:sorry to here :( i hope i dont get these horrid issues when mine comes in

i hope toyota and subaru really do some heavy duty glitch fixes

Immediately after a reflash, the car will be down on power and feel sluggish. That's because the reset of the ECU will clear the learned values, so the ECU will be using a known safe calibration. As you drive it, the gas pedal will get sharper and the power will return. I haven't done this with my BRZ yet, but my STI behaves the same way and it takes about 20 miles or so for it to feel normal again.

During my audio installation I had the battery disconnected, and after I'd finished and reconnected the battery, throttle response was quite noticeably sluggish. After some miles (maybe 50-100mi?) it began to feel like normal again. I don't believe this was any sort of placebo or me "getting used to the machine" because I noticed for the same amount of foot movement the throttle responded more quickly and accurately, as it did before.

I say give it some time and some miles (including some full rpm runs through the gears) to allow the ECU to learn and adjust it's parameters again.

resetting the battery after a new ECM is replaced will have no effect due to no learning values being stored in the ECM. one thing i can tell you is drive it like it new (may not want to pass 4k RPM's) because the ECM will learn normal driving habits and this is good because when you get on it the ECM will know your in a panic and give more performance.

:happy0180:

Hopefully it does go back up to normal levels, because if it doesnt it simply is not acceptable. Im still trying to get my idle dip fixed and the last thing i need is for it to get fixed and for this to happen permanently

If I get a chance this week I will throw mine back on my dyno and verify power. It feels around the same I think.

You're gonna have a long wait if you have the same issue I did, my friend. Dealer tried to reflash my ECU but no dice. My car has been rotting at the dealership for the last 3 weeks, awaiting a new ECU to arrive. :mad0260:

:(