110bhp diesel 2000 AHF,there was a big flat spot after first starting and pulling out onto the road and putting your foot down, ECU said is was air mass meter (next to air filter in tube ) just changed it and now have hesitant pulling on a light throttle with new device, any thoughts as I am pulling the caravan at 2 ish :confused:

It turned out to be a faulty Air Mass flow Meter, it was the cheaper one (