Loss of power, Loss of mpg

[S33KRP]

I have a mk5 golf gti with a stage 1 revo map.

Before the map I had the pcv valve, diverter valve and cam follower all replaced.

Over the last few days I have noticed a drop in performance and also a drop in mpg, no faults in the memory.

Thinking it may be the pcv valve or maf sensor.

Any recommendations

TIA

[Wash]

Would start with a diagnostics scan before replacing any parts bud as it should point you towards the right direction. No point replacing random parts hoping to fix an issue.

[S33KRP]

Agreed, had it scanned and no faults.

So contemplating going to revo to see if the map is still active as the battery has been disconnected for a minute maximum

[Dan_FR]

If you have had the battery off at all, even for a second, then the map defaults to a low power setting.... The difference between this and your normal settings should be night and day

[S33KRP]

I understand revo say that the map reverts to OE after battery being disconnected, but myself and several technicians cant see how this can happen as it is embedded in the ECU.

Also if that was the case the car was driving fine for around 3 weeks after this had happened   

[Dan_FR]

It doesnt revert to OE software, it reverts to OE equivalent power output in terms of boost request due to the fact that Revo offer switchable mapping and the way in which the selected map is held in the ECU memory

If you've been lucky and the ECU has managed to retain its memory (residual charge etc.) then it saves you a trip. The difference between Revo stock and Revo Stage 1 on the GTI is night & day - the car feels broken, flat and lifeless going from Stage 1 to their equivalent OE output

Some more info would help, such as when you had the Revo software done, when you started to experience issues, whether the issues started at the same time you had the battery off etc.

[colesey]

I have revo stage 1 also and all you need do to is reboot it with the SPS. 

[pudding]

The difference between Revo stock and Revo Stage 1 on the GTI is night & day - the car feels broken, flat and lifeless going from Stage 1 to their equivalent OE output

It certainly does!  I too thought mine was broken after replacing the battery on mine.  Didn't know it was Revoed at the time.

I believe only VWR revert to the actual factory map in the same scenario.  Every other tuner just reverts to a 'stock like' map which is often bloody awful.

[S33KRP]

OK, the map was put on a year ago, the battery was disconnected around a month ago, and the issue has happened the last 2 days.

Ive spoken with my local Revo and Revo UK and im going to take it in Thursday to be looked at as they are saying, 'the MED9 ECU has no memory, so the settings will be lost and default to stock' so will see what Thursday brings back 

[Dan_FR]

Nothing to do with the Revo software then so will be a wasted journey

Check the DV would be my first piece of advice, after that check the fuel trims with VCDS