hi there, had problems with dropping revs at junctions and general poor driveability mainly light throttle off boost. anyway cleaned the icv and maf a few weeks ago which made little differenca at all. this weekend had the tmic off again to look for splits but nothing there that i can see. whilst the tmic was off re tightend up any hose with clips on up nothing really amith there. also took tps connector off and sparayed sas spray on the pins just to clean any possible bad connections up. put everything back together and thought id try leaving the 02 sensor unplugged for a while. took it out for a spin today and the car was a lot smoother and the dropping revs had virtually vanished?
so now left wondering weather its the 02 causing alot of my problems or the tps i cleaned up or anything ellse i played with. i think the next port of call is to plug it back in and see if it goes back to how it was. even though this may be the problem i still had slight hunting on cold start and now only very very slight once warm but remember this is with no 02 sensor at all so would a new one improve things even more? i am no expert but wont the ecu be running preset map if no signal is being received from the 02 sensor. sorry for the long thread but this is quite a big problem it seems on imprezas so im sure it can only help others as well as me. anyone?

 

I had a 'dying revs when cold problem', and a 'misfiring idle' cold & hot. I didn't touch the MAF or ICV, changing the spark plugs and coil packs solved the problem for me.

 

i am having a similar problem, wont go into detail here but check

https://www.scoobynet.com/general-te...-dropping.html

i actually found exactly the same thing, unplug the o2 sensor and the car runs almost perfectly. i have replaced the 02 with a universal but its exactly the same when plugged in. have new MAF coming tomorrow. the other thing i have noticed on mine, is that sometimes it will idle ok. the hunting is bad but given a chance it sometimes settles down (before starting again next time i stop!) i am lost on this one!!

 

try bringing ito subaru for a select monitor check for any wiring deterioration which may cuase fluctuation in the select monitor reading. I am also having the same problem but try to conpensate it on the iac valve adjustment.

 

Ive got a similar problem at the moment which is getting very annoying but im running a link g3 ecu,so no maf is used.

Could somebody please confirm what the ICV is so i can check/replace it

Also the o2 sensor you speak of, is this what some would call the lamda sensor which sits in the downpipe just by the turbo ??

Cheers for your help

 

can anyone help ?

 

 

im having this problem aswell now started 5 days ago, i have been told to change plugs and then to have the injectors looked at. this is reasonable costly so any other options would be greatly appreciated as the advice was just from a mate of mine who hasnt had this problem.

 

I had the same a while ago.

Turned out to be the dump valve. Very common problem apparently. Went back to the re-circ and has been fine ever since.

 

Mine is not dump valve related as ive not been running one for a long while