Low power after turbo and EGR replacement

Hello everyone, I'm hoping someone can give me some advice concerning my 2006 Superb 1.9 TDi, It's just reached 140,000. The turbo started to make the whistling noise recently and when it was idling it would chug for a few seconds and then run normally again also on the rare occasion I really put my foot down the power would suddenly cut out although it would return after a restart. I replaced my turbo with a brand new one from Skoda and had the EGR valve replaced at the same time also with a genuine Skoda part although both were fitted by my local mechanic, I had the timing belt done too for the second time. After all this the chugging whilst idling has almost stopped completely (it happened once for a second and was very slight) and I can put my foot down and the power no longer suddenly cuts out. I was told to expect a bit more power after the turbo and EGR, unfortunately this hasn't been the case even though it fixed the other problems. It feels generally underpowered now, more so in the lower gears with the change from 1st to 2nd feeling particularly uncomfortable, especially on a hill start and it also seems to suddenly surge under acceleration in a way I've never noticed before. I've also noticed a smell from the exhaust that wasn't there before the work I had done which I can only think to describe as a hot oil kind of smell. I've made an appointment at my local Skoda dealer on Monday to have my MAF sensor checked and replaced after reading some posts here that sound like that could be the problem. My question really is is the MAF sensor likely to cause the symptoms I have and if it doesn't help what else should I have them check for following the kind of work I've had done ? I should probably mention that the cars never been on any kind of dealer diagnostics equipment and isn't displaying any fault/warning lights and I've owned it from new. Thankyou for reading and thankyou in advance for any advice offered....