Dear customer, the increases of pollutants in the exhaust gases are mostly due to the fact that the vehicle can not regulate its mixture correctly.
The mixture inside the cylinders must always be stoichiometric (equal amount of fuel with the same amount of air) when we have problems in the mixture, the exhaust system contaminates more than the normal by the bad regulation of the combustion, effectively as well you indicate me, you have a judder or tremor in the operation of the engine, this tells me more to me than indeed if you are presenting faults in the same engine and therefore the bad regulation of the mixture.
I am going to recommend you to perform a good general maintenance, this maintenance consists of:
A replacement of all filters first, both fuel and air.
A cleaning of the injectors and checking in a test bench to observe that these are correctly spraying the fuel and injecting it, evenly in all.
A cleaning of the throttle body, disassembling it completely washing it and placing it again.
It is good to check the pressure of the fuel pump that is close to 50 kPa and that is not falling, if not, replace it.
Check the condition of the spark plugs, if you have time without replacing them do it, to make sure they are burning completely and correctly all the fuel.
Dear customer, with these maintenance very surely your problem in the regulation of the exhaust gases will improve and the vibration will go away.