Vivaro low power, limp mode

[Jamiehall30]

So I have everyone’s favourite mechanical nightmare, a 2006 1.9 Vivaro.

I keep getting low power and then it’ll drop into limp mode until I restart the engine. I’ve changed he MAF sensor and that hasn’t worked. Interestingly if I drain the fuel filter and hand prime it the van runs fine for a few miles (I presume the amount of time is takes to drain the filter housing).

Any thoughts that don’t involve the classic EGR MAF etc?