check engine

[1dollae30]

ok so i recently got a head gasket job done to my 89 325i adjusted the vlave it was all fine until the other morning the check engine light came on. it idles rough but as soon as the idle smoothes out the light comes on tap the gas and the light goes off can some one point me in the right direction dont have a job so cant afford to put it in the shop for anything else

[jlevie]

If seen this happen when there's a small intake leak and when the O2 sensor is bad. An intake leak and a bad O2 sensor could explain the rough idle and the light.