I have 2005 subaru forester. my engine shakes all the time especially when it is idle. when driving i dont feel the shake but when i stop it shakes. i have replaced my plugs but still shakes. also when i accelerate hard or driving at a speed of about 80mph i smell something like rotten egg smell even if i hv rolled all the windows. No check engine like too. it only comes on after i turn on the key but goes after i spark it.

It helps to let the engine idle for a minute or two. Then while it is idling if the fans turn on, wait until the fan shuts off, then turn off your car. Also you must let the engine warm up before driving away in it. If you do these things your engine will not shake on you anymore.

First step is to access the Engine Control Module (ECM) using diagnostic equipment connected to the data link connector of the car, in order to pull out all Diagnostic Trouble Codes (DTC) memored. Even if engine Malfunction Indicator Lamp (MIL) goes off after engine starting, it's possible to find out temporary DTC codes memored in the ECM. Then you will be full informed about bad components (e.g. bad heated oxygen sensor(s), cylinder(s) misfire(s), bad injector(s), bad ignition coil(s), ... etc). Therefore you will be able to repair & replace bad components and reset the ECM.
In the most cases when you smell something like rotten egg there are bad oxygen sensor(s).