[DrFeelGood]

Hello,
Which tube did you inspect and at what point?

P2144 code, EGR how to fix?

Your shifting issue could be a result of the charging system. The TCM is a bit finicky with its power needs.

 

[DrFeelGood]

It's a small world. The Mazda 6 in the video is currently my car. I purchased this car for my daughter shortly after the video was made. I verified the license plate in the video. One thing curious about the mechanic's video is that he uncouples the EGR tube leading to the exhaust system "at the exhaust system" when it's much easier to uncouple the tube at the base of the EGR. Also he kind of indicates the two holes in the tube assembly (one on the side and the other in the end) should be the same size. This is clearly not the case when inspecting this tube as the end hole is drilled smaller for some reason. When inspecting this tube I found that it is not clogged. All that said, the video was still helpful and I appreciate people like this taking the time to make and post these. The battery, while starting the car, is only registering 12.4 volts. I've put a charger on it to see if I can bring it up.

Huh, how ironic. Something about this rattled a memory cell in my aging parent brain.
The code you posted (not used in my 2004) is referring to a similar issue we have as a P1487.
There is a good diagnostic write up listed below.
Another case of EGR Codes P1487 P2227, SOLVED!

and also below
Help! Codes P2227 and P1487!

Maybe these help.

 

[DrFeelGood]

Thanks for providing these links, and the included links to manuals. Quite a bit to digest, and I'm not electrically savvy, but this is all very helpful.
Mike

In that case, just replace the EGR solenoid.
It may fix that code and possibly give you another for the barometric sensor after, but you can cross that bridge if you get to it.