check engine light on/off

[marc turp]

First let me thank who ever started this i just found it and can see many days spent here and then hearing about it from the wifey any way this is my problem. i have a 1995 318is and when driving on the highway or steady on the gas the check engine light comes on but as soon as take my foot off the gas it goes right off i have a peake code tool but all that tells me C9 emission (lambda) control please help.

[marti5]

Thats the o2 sensor, if this is playing up it can and will illuminate the engine check light, all thats required is change the sensor, a DIY job if you ok with mechanics.

[marc turp]

which one upstream or down or should i replace both and does anyone recomend which brand to use

[marc turp]

and yes i grew up in a auto salvage yard so i have always done all my own work to cars

[marti5]

Up or down dont really know by that code, normally its the pre cat one that seems to go, but dont quote me on it, I use Carsoft diagnostics which is more precise, as for make I always buy my new parts from BMW, but have a look at ebay there are a couple of places the chaps here use but I cant remember there names as im in the UK and use different people, think ones Bavauto something like that, sorry.