During my last flights I noticed that at some point the last two cylinders on the EGT diagram were running cooler than all the others and the ones marked 3 or 4 were much hotter than the rest.
This is an example. In this picture the fuel flow is already more than what it used to be in the past and so is the TIT. Before I was able to run at the same altitude (FL200) at something like 15.8 – 15.9 GPH and TIT of less than 1580. Now it is as shown and the engine stumbles a bit here and there when I try to go back to the old values.
If I enrich the mixture a bit more the stumbling stops but now I’m running much hotter than I would like to do. The EGT difference between the cylinders changes a bit – most are getting a bit closer to each other – but the two laggers still lag behind. Apparently now they get enough fuel to not stumble anymore.
The aircraft is an SR 22 turbo-normalized. Do I see the effect of clogged injectors here?
The items which are individual to a given cylinder are
It could be injectors. The procedure is to soak them in MEK (nasty stuff, and like most things that work it is hard to get 
) and blow them out with compressed air.
Also, if you had GAMIs installed, sometimes a shop puts them back in the wrong holes. I had that happen once. The engine still runs but you can get pretty weird results.
Do I see the effect of clogged injectors here?
First off, absolute EGT values say little. But I guess you wanted to say that, coming from rich side, the last two cylinders peak much sooner than all the others, right? So, yes, in the is case, it could be clogged injectors (although it is not very probable to get two of them at the same time). Get them cleaned on the next occasion.
Either clogged injectors (rare) or injectors that were undertorqued upon installation and vibrations work them loose allowing the engine to suck extra air through the thread and run leaner than usual.
The items which are individual to a given cylinder are
the spark plug
the ignition lead
the magneto
the fuel injector
the fuel distributor
The exhaust valve
The inlet valve
The cylinder
The head
The EGT probe…
My bet is on exhaust valves…
https://www.savvyanalysis.com/articles/understanding-cht-and-egt
Cam you download the data and upload it to savvyanalysis.com?
Uploading the engine parameters to Savvy and checking your GAMI spread, comparing it to previous observations, might tell you what is going on.
Check for vacuum leaks, loose intake manifold clamps, hardened intake hoses and the like.
