I have Subaru legacy 3.0R, the thing I feel sometimes that my car take time to responds to (accelerator). So let say I fully pressed on gasoline so it might take 4-5sec to response which I feel it high latency.
I hope that I delivered the right idea about my issue.
If the check engine light is on, have the computer scanned. If not, check to make sure the fuel pressure is within spec. Have the throttle position sensor checked. However that should set the check engine light.