Hi, I had an intermittent engine miss, and also a general lack of power. The milage on this subie is 70,000. The CEL never came on. I tried the obvious, fuel filter, plugs, wires. I finally let local shop have a go, they couldn't find problem. I then decided to try closest dealer. They diagnosed as worn clutch, $1,100. I declined their offer and paid $44 for diagnosis. I had searched this NG and found a few other posts that had similar problem. The front O2 sensor was the culprit. I changed the sensor and car has been running good ever since. Initially when the problem started, I was sure I had water in the gas. I even used dry gas and the symptoms didn't seem as bad. The problem persisted for months. It was most noticible when climbing long hills, miss fire, run o.k., miss fire. I wish the CEL had come on, it would have been easy to diagnose. Hope this helps others with similar issues of poor performance.