So I use my fabia mainly for delivery driving drive it nice and smooth but trip indicates 38mpg which is awful and I know they over read so probably down at 30ish no engine lights no smoke idles fine hesitates a little at low revs and slight throttle also think I'm a little down on power having it scanned tonight but don't know what I'm looking for thought it might be the MAF so unplugged and if anything it drove a little better but im led to believe this is irrelevant as they run of the map sensor I have replaced the thermostat and have a cts on the way but don't think this is the problem car has 204k have looked inside the egr and that's not caked up at all so need to know where to start before chucking money at it thanks? 

MAF does affect fuel economy, so changing it will help. Try measuring the real economy figure by filling the tank to the brim then measuring the mileage to the next fill up.

Thanks for the reply I measured it at about 33mpg give or take obviously town driving is not ideal but would expect low 40s as I drive like a grandad 

So scanned and had codes camshaft position sensor intermittent and mass air flow something.... Have cleared them and will rescan tomorrow to see what appears again 

MAF will appear again, you should check the torsion value as that can cause intermittent CPS faults and that will also affect fuel economy.

Driving like a complete animal, I cant get my Fabia VRS below 40mpg, and driving sensibly 53-55 mpg, so something definitely not right. 

 

I would suggest running a compression check on the engine to make sure each pot is up to scratch, and the valves are sealing as they should. N.B. make sure you are using a diesel engine compression gauge!

I have now changed the MAF sensor and am getting 40mpg doing start stop delivery driving round town and 50s on the open road so think all is well engine seems to be a hell of a lot smoother happy with that mpg from a 205k engine despite getting 40mpg round town display says 54.5 mpg shocking how far out that is 

@CLARKVRS1492 How is the hesitation on light throttle now?

10 hours ago, HeavyMetalRich said:

@CLARKVRS1492 How is the hesitation on light throttle now?

Had completely gone can't believe the difference the MAF has made