Bad gas mileage = Bad ECU?
 

so i took my car in to Mazda today for a list of problems including CEL flashing, car stops accelerating, door rattles, and oil light comes on at high speeds...just for fun i also threw in bad gas mileage...you know what they said? there's a new ECU reflash that fixes the bad gas mileage...of course i asked them by how much does it help and of course they didn't know...i'll keep you posted if i see a difference but i'm not holding my breath...

also, they supposedly fixed all my problems with a total of 2 ECU reflashes, 1 for the check engine light and bad gas mileage and 1 for the CEL light and the acceleration problem...if they told me they fixed my door rattles with an ECU reflash i woulda cried...

Is this reflash for the bad gas mileage available to everyone, or do you have to have a warning light showing?

Go put some miles on the car and let us know. Hopefully your MPG goes up to 22-23 which would be a nice New Year's present for all 8 owners...but I'm not holding my breath :p

More snake oil cures........Jeez, everyday a new post on how they fixed the mpg saga. Has any of them actually worked?

If this does indeed work for you, and you can back it up, I'll apologize. I would like a little better fuel economy.

I had a check engine light come on several times and it was this problem http://www.finishlineperformance.com...01-024-03.html . Since Ive had this done my gas mileage has gone up from < 15mpg to > 17mpg. If your vin is listed in that bulletin you may want to take the car in and let them know. Its not a huge improvement but well worth it imho.

better gas mileage would be good fore sure however you gotta figure in order to flash the ecu and make it get better mileage it has to effect the HP somehow cause it probably sends less gas in each combustion of the engine.

I actually had my engine replaced, and then my ECU flashed. At first I thought the mileage was better (it got down to 12-13 right before the engine failed). My new engine consistently gives me 15 MPG or so- no more no less (~205 Miles on 13.5 gallons at fillup). This is what my old engine had before the ECU flash.

Re: Bad gas mileage = Bad ECU?
 

didnt you know they have a new ECU fix, they can flash it and have every bolt/connector/screw automatically tighten on thier own :) ECU fix for everything haha


*** NOTE ***
for the newbies that really dont know i am joking

like i said, i'm just as skeptical about this as you are...i was seriously joking when i told the technician to add bad gas mileage to the list of problems i was having...i guess he really did add it in and when they called me they told me that "the bad mileage is related to a PCM reflash"...

i got the car back and it feels no different, even after the oil change and ECM reflashes...NO it doesn't feel any faster and they didn't fix the rattle in the door...i wasn't able to hit 80 to test out the oil light problem...we'll see about the mileage after my next fill up

i wonder if they got an ECU fix for my receding hairline?

BRx8

What is the PCM Calibration Part Number of the reflash? This can be found on a sticker under the hood and should be a number like N3H4-18-881K.

i don't see that...i have only 3 stickers under the hood: port campaign sticker, air conditioning warning, and a routing diagragm for the vacuum hose, i believe...

on the paperwork, it lists the cause of the CEL as

EGI DIAG
F0008XDX EGI SYSTEM, DIAGNOSIS

and the cause of the low oil warning as:

F0010XFX POWERTRAIN CONTROL MODULE - REFLASHING

did the ECU flashing seem to lower your HP at all?

that would be great if you could get better gas mileage and not sacrifce any HP

What about mid-life crisis? :D

can't really say right now...

1) it's 15 degrees outside and there's ice on the ground so my tires spin out of control if i push them

2) i picked it up after work so it was rush hour...

i did get a chance to push it a little and i'm probably just lying to myself but it seemed to give a little push around 5000RPMs and there wasn't as noticeable of a dip at 6250RPMS...the same 7250RPM push was still present...again it could all just be the weather conditions and myself lying to myself...if there is a difference at all, it's not noticeable and not even worth mentioning...it's definitely not any slower at least

cool,

now i gotta figure out if the dealership will flash it free before i buy the car

i wouldn't bother...i'm sure if you bought the car now it'd have the newest program...i was just part of the first owners that got dumped with the hacked up ECU...my VIN number falls between the ones that are effected by the low oil light and CEL problem (numbers ending in 0000 - 1043 for the low oil light and 0053 - 9374 for the CEL)

edit: of course it wouldn't hurt to know you have the latest and greatest...hehe

Better gas mileage does not have to equal less HP. That would mean that all you need to increase HP is to just dump more gas in for each combustion. Not how it works.

actually better gas mileage *could* even mean better hp. if the ecu reflash makes your engine more efficient it's conceivable it could have more power/fuel. giving it both better hp and better mpg.

Just had mine worked on Monday. They replaced the oil pan and the clutch bearing. I will call and see if they did the reflash also. If not, I'll get it done next time I am at the dealer.