97 wrx idle?

[toad]

hey. my wrx idles funy. it will go from 600 to 1200rpm bouncing? wondering if any1 culd help?

[WRXONP]

hey bro i had practically the same problems man... for me it turned out to be because i didnt have a o2 (oxygen) sensor in the downpipe...i fitted one and all is good...

a bung o2 sensor would give same symptoms as having none so maybe something for you to look into??

[toad]

wicked thanks dude

[WRXONP]

you can test the o2 sensor with a multi meter bro if u have the know how and a meter...just to see if thats the problem man

but yeah theres a few threads on here about my idling problem...mine was idling lumpy as up and down sounded like it had cams...turned out it was because there was no o2 sensor on there and the ecu had to make a fake o2 sensor value which in return makes the idle crap

[Guest]

i seem to have the same problem, how do you test the 02 sensor? checking for resistance? if so what sorta numbers are we looking for?

[WRXONP]

Na man you test it for voltage output . The way I was taught was to hook multimeter up to the signal wire on the o2 sensor and earth the meter to the battery . Have the engine up to temp as the o2 doesn't work when cold . On hot idle it should ping between rich and lean . I cant remember if 1v is rich or 1v is lean but basically im saying 1v is rich and 0v is lean . 0.5v is stoich (lambda which is 14.7 :1 air fuel ratio ). It should be bouncing quite quickly between around 0.6 to 0.4 . Another way to test is to create a vac leek on the manifold by un plugging a vac hose or similar and see how quickly the o2 has a lean reading . I hope some of this makes sense to you and if you need further help just ask me and il try my best . There is other ways to test them . But this is the way I was taught and its a simple and effective method

[Guest]

yup that makes complete sense, i have a wideband 02 sensor and gauge and my car is running way to rich as well as a funny idle. so this could quite possibly be the problem?

[WRXONP]

Yeah man id say you might have a bung o2 sensor then . Do the test and see what u come up with . Also see if your wide band comes up lean when you have the air leak

[Guest]

yup it was o2 sensor, running a lot better now. cheers man great help

[WRXONP]

Ha sweet bro !