Engine subtle vibration / shaking tail tail sign of near clog catalytic converter

Engine subtle vibration until the dashboard area but there are no error fault codes when diagnose using the OBD2 scanner device. What could be the problem? This is happening to Alza car and the vibration still ongoing for quite sometimes. 

Apart from the vibration when the engine starting at cold start (early morning) strong smell like rotten egg emanating from the exhaust and of course the car unable to accelerate at full speed on the road despite pressing the gas pedal at full throttle. This is because the clogged catalytic converter suffocating the engine from breathing normally.

OBD2 fuel trim data also showing very rich exceeding the benchmark below -10% | +10% and it may spike up to -40% which is extremely rich or +20% for extremely lean. This is a sign the unburn gas during cold start unable to fully escape through the exhaust manifold catalytic converter and generating kick back which affect the oxygen sensor reading. So basically, exhaust fume generated from the combustions plus the kick back of unburn fumes caused the oxygen sensor to read extremely rich. However, pressing the gas pedal during cold start will see the fuel trim reading back to normal within -10% to +10% benchmark as the unburn fume being force through the clogged intake manifold.

Potential problems creeping from a bad front wheel bearings

After an experience replacing front wheel bearings lately - there is a feeling it's one of the most important components of the wheel that need to inspect occasionally and require replacement as soon as possible if it has gone bad. The wheel bearing is a very strong component that also helps to assist the suspensions to keep the car stable while driving on the roads. 

As the wheel bearings worn out it weakens the grip on the driveshaft and causing the wheel to wobble. If left too long for example years without replacing just because it's a minor wobbly the problem could creep to the cv axle differential bearings inside the gearbox which hold the inner end of the driveshaft. This is because the wheel bearing could no longer hold the driveshaft firmly on one side and automatically yank the other end back and forth which is being hold by the differential bearings.

And of course, replacement of the differential bearings will cost more to replace, and it require special tools, effort and time to get it done.