"Repaired" ECU drops 8-9 MPG

[NeilBlanchard]

I've owned the xA for ~6 years and 7 months - but it has ~139,000 miles on it.

[user removed]

Was the repair something due to a complaint or something they decided to do on their own?

[Piwoslaw]

Originally Posted by Quezacotl

What you mean out of spec?

Out of spec means it's not using enough fuel. Gotta get it back down to EPA, that's the plan.

[wdb]

I'm with the "ECU needs to relearn" crowd. Here's hoping that your mileage returns!

[NeilBlanchard]

We'll see how it goes. The odometer is indicating a little over 200 miles at the half full mark, where I have been getting ~240-250 miles. I had an unusual couple of days of driving right at the beginning of the tank -- short drives just within the very small town I live in. Since then I have resumed more typical drives; and I have now eeked the SG II up to 39.2mpg.

I hope the ECU "learns" quickly?

[Cobb]

I looked on ebay, seems ecus run from 75 bucks to about 150. Have you gone back to the dealer? Have you called your bank to dispute the charges?

I had an xa for 30 thousand miles, got 37 mpg worse, mid 40s best. It liked to cruse at 40 mph in 4th gear.

[NeilBlanchard]

I'll see how this tank goes (I've got it up to 40MPG!) and then ask if the "fix" is reversible.

[Phantom]

I do not know if the ECU made by them is slow but a car should only take at most half a tank to relearn most likely less if it was reset (disconnect battery). The 93 Bonneville's only took half a tank to fully learn, the 98, 2000 and 2002 if I reset them (I did it with a tuner) could relearn in 50-100mi.

Originally Posted by NeilBlanchard

The spec they wanted to fix had to do with a temperature threshold being a degree or so off. It was fine (other than a leaking water pump).

That issue would most likely be a temp sensor was off and should have been replaced to correct the issue. If it was a turn on/off point that the ECU uses and the sensor was working correctly then they should have flashed the update or reflashed the current version of the ECUs tune.

[NeilBlanchard]

The MPG's are climbing - 41.3 now, and because the tank started so badly (<38) that means I am doing pretty well. The ECM does seem to be "learning". Also, I am getting brand new set of Nokian Hakka R's tomorrow, so this tank will be an outlier for several reasons.