Cutting out on idle

[BenDover]

Hello all, 

I’ve recently bought a 2007 rav4 t180 through a friend who buys and sells cars. It’s got a couple of issues which I don’t really understand. Initially it had a lack of power between take off and 2.5k rpm then all of a sudden the power would hit like a train. The best mpg I have gotten was 18.2mpg and I’ve done quite a good amount of miles in it whilst being conservative too. It threw a bunch of warning lights on recently and cut out at idle, then refusing to start. When it did it had no throttle and died again when I tried to rev the engine. It threw the EML light, VSC and 4x4 system control light, with x6 P1229 codes. Now it won’t idle for more than 35 seconds without cutting out, it doesn’t run tough the die either. Just cut out. The engine idles extremely rough sometimes too, really lumpy with the revs jumping up and down, then it’ll calm down and idle fine after 5 or so seconds. I’ve replace the fuel rail, high fuel rail pressure sensor, suction control valve, fuel filter, programmed an Injector the previous owner had replaced but failed to programme it to the vehicle, cleaned the egr valve out. There’s no leak back from the injectors either. Doing this made zero difference, actually changing the suction control valve made things infinitely worse. 
Any help or advice on this issue would be greatly appreciated thankyou.

also I do work in a small fast fit centre myself so I have access to tools, ramps etc. 

Edited June 6 by BenDover
I left something out