OakleighParkScoobie

2 questions!

I have a 2001 WRX and under hard acceleration I get what feels like a series of small miss fires. The plugs have been changed twice, tried another set of coil packs, and a new MAF sensor but to no avail. I understand that cleaning the boost solenoid may well help but it would be good to know if there may be anything else that may be causing this?

Secondly, when at low revs (2000 rpm) when you start to accelerate the car seems to hold back for a split second. I have read in other threads that this could be the lambda sensor but am I right in saying there are 2? One on the downpipe and one in the centre section. I replaced the one in the centre section about 3 months ago as it was giving low output reading when hooked up to a main dealers computer, but recently my engine light has been flashing under hard acceleration, about 10 times, then goes off again which according to the handbook is something to do with emissions. The car also seems to idle low, about 500 rpm according to the rev counter, but shows between 680-730 on main dealers computer.

Any ideas on these would be much appreciated!!