Have a 2007 2.2 5 speed 260k miles
About 2 years ago it started hesitating under light load.
Overtime it progressively got worse but goes away if I put a bottle of fuel injector cleaner in it.

Now it's gotten to the point that it DEMANDS a bottle of fuel injector cleaner with EVERY tank or it does the chugging, and Will get downright cranky and even won't idle right ,chug and miss under normal load without the fuel injector cleaner.

With the fuel injector cleaner or running it hard it's just fine. No codes other than the catalytic converter which is hollow.
New Spark plugs and coil packs didn't make any difference,and I always use good gas.
Fuel pump has proper pressure.
Not really sure what else it could be unless anybody else has some ideas.

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Welcome to the site , give the throttle body a good cleaning and the MAF sensor
CRC offers a kit for this with specific cleaning sprays for each parts

Do not move the throttle plate manually, this can strip the plastic gears in the throttle body.
to access the other side of the plate remove the 4 10mm head retaining bolts lift the throttle body off the intake manifold and spray the intake side of the plate, you can use a small nylon brush to scrub any dirt away , but it’s not usually necessary.

A simplified video

 

No Check Engine Light? That is strange.

 

What does the scan tool show? Does it connect? Does it find all the modules?
The way it's running the CEL should be on.

 

Ever think maybe the computer is calibrated for a good catalytic converter?
So, we know there is one code, P0420, that masks some other codes.

 

No codes yet apparently, let’s not invite trouble

 

From the OP:

 

So, the CEL is always on and the cat code is the only code?
You have misfires?

 

Missed that one, is it P0420, because of the hollow catalytic converter?

 

Already done that with the exact same kit that you recommend.
I usually do it about every 6 months and have since the vehicle has been about 5 years old.
I also do a seafoam treatment with the deep creep at the same time.

The throttle body is spotless, and I just cleaned that and the MAF less than a month ago with the same kit that you suggested.
I was considering replacing the MAF but I don't want to spend money on that if it could be something else.
However, I have also been manually pushing the throttle plate all these years, so is this possibly a symptom of stripped out gears now and I need to replace the throttle body?
And/or is that the type of symptoms that happen when the MAF is bad?