I've got a 2012 1.6tdi Bluemotion Golf, manual trans, CAYC engine that after a basic service by independent, but VAG literate garage, has poor fuel economy (6-7l/100k vs 4.5-5.5 before). The tyres were done at the same service and I initially suspected the tyres, however in retrospect the degradation is way too high to be tyres. I took it back and NFF. Car otherwise runs fine except there is a slightly rough idle when first started. No relevant faults shown in VCDS. Now, 2 years later, based on googling it seemed that MAF sensor was most likely culprit I replaced it about a month ago and hey presto no change! So wondering if anyone has seen a similar issue or has any suggestions? I've checked the air intake pipes/hoses and there does not seem to be any obvious damage.