So I started having a problem on my way home from work one day. Yellow check engine light and I used my reader to find codes 1497, 0507, and 2188. The rpms when when the car is warm and im stopped go up to about 1500-2k slowly then drop and repeats itself.

I know what the codes mean for the most part. Only upgrade is a KN cai. I cleaned the filter and maf sensor. The maf sensor actually did make a performance difference. Car has 65,000 miles on it and I have owned it for a year.

Also I have noticed some random power issues when I get on it. I do have very slow oil leak from the turbo and when I was cleaning my filter I noticed one of the ridges has no fabric on it at all and cant remember if that is normal or not and KN is taking for ever to get back to me.

So I am assuming valve cover I can here an air sound when its running but I cant find where it is coming from. I always use premium gas also.

Im sure I can replace the valve cover myself but I would hate to just waste the money if it isn't it. I checked and couldnt see any cracks or anything and I have changed the spark plugs withing the last 10 months. So I am really just looking for some help so I can try and diagnose the problems myself.

Any ideas are greatly appreciated and feel free to ask any questions