Rich fuel trims

[Jimmyk]

Hi all, I posted on this forum last year about my car ,lumpy running,well this has been an ongoing thing,been all round the houses with different fault codes showing,have been working my way through the codes short story long,the latest code,(in a long list} is p0170,what is happening is on live fuel trim data in open loop,start sits at 0.8%then when changing to closed loop goes to _25% and ltft sits at 3.9%.the thing is I have been messing about with this for ages,have changed most sensors,02 sensors,thought after a lot of messing about ,thought it was the cat ,no change,plugs and o2 sensors very sooty,have done smoke test checked wiring,latest is done a vacuum test,this was saying valve timing slow,bingo I thought,however when timing engine, you use pins in camshaft and flywheel at Tdc so I don't see how valve timing could be out?anyway where I am now is I have the head off for decoke and clean up(very sooty)the only thing I haven't changed is the Ecu,I was going to send it to be checked,I am pretty sure that once it all goes back together it will still be over fuelling,have changed injectors and map sensor, does anyone have any other ideas,by the way I enjoy a challenge,however don't see any end to this,the car is a peugeot 307 1.4 8valve Sohc 2003 with 58000 miles,any help appreciated,cheers apologies for long post