HI ALL IV RECENTLY PURCHASED A 05 plate 2.0 wrx with sti box, pink injectors, machined ici turbo , ecutek map, brembos, sti intercooler,hks dump ...... every now and again with in hours days weeks il pull up at a junction and revs will drop to stall and it will drop rpm hesitate sec or 2 then boost...feels faster on occasion. when bought was told cel light has always been on o2 sensor is culprit..... within 2 tanks of vpower driving like grandad it went off........ now its back on ...???!!! do i need wide band o2 sensor and a remap??? or just take bulb out..... ALSO..... has standard airbox... can i change to k n n panel with out remap.... can i change back/box without remap...
THANKS IN ADVANCE ANY HELP :-)

 

read the error code and report back,
who buys a car with CEL light on, and not know exactly what it`s for . . .