Episodes of the 4kids series that reminded you of the original cartoon
 

In "Rogue and the House," Shredder/The Foot creates a robot Splinter to go and lure out the Turtles. We've seen a robot Splinter created by Shredder/Krang in the original cartoon.

The Evil Turtlebot, copying all the turtles ninja moves, was essentially the same thing as Metalhead from the old series.

The first Turtle Titan episode was very similar to the first Bugman episode in the OT, even with the other Turtles not believing Michaelangelo met a superhero.

Any others?

Well, I haven't watched all or even much of the 4Kids series, but the Garbageman episode is the first thing that comes to mind. Classic good versus evil.

When Donatello mutated into a monster at the end of Season 4, the same thing happened in the old toon with Leonardo in Season 10. I remember a line Leonardo said in the new toon: Had it been one of us, we would have turned to the genius Donatello to save the day, which is exactly what they did in the old toon, with Carter's help.

2 episode names were used in both cartoons: Beginning of the End and Adventures in Turtle Sitting.

In Enter The Jammerhead, after he got out of jail, he looked a lot like Chronos from Split Second.

In Turtles In Space Part 1, Michaelangelo asked, how come bad guys always get all the cool toys? In The New Mutations, Michaelangelo asked, why should Dregg get all the cool toys?

All those mutants from Notes From The Underground reminded me of HAVOC in the old toon, both plots involved innocent people being kidnapped and being turned into mutants to be slaves.

When the turtles traveled to ancient Japan in Secret Origins, that was a lot like the Legend of Koji, when they also went to ancient Japan.

"A Better Mousetrap" and "Attack of the Mousers" clearly has some elements of "A Thing About Rats", complete with mouser demonstration and mousers attacking Turtles/April/Splinter.

Most of Fast Forward and Back to the Sewer, and the two Garbageman episodes. Man, I hated those two!

Mission of Gravity is like the 2k3 version of Sky Turtles.

Totally. It had trench coats and fedoras, a cheesy villain, Michelangelo surfing on impossible sh*t, and a cowabunga lol.

That one episode of BTTS had a mad scientist that was very similar to the old toon mad scientists.

I honestly wondered if the entire 4kids run could go without a single mad scientist. I was wrong.

I don't think that counts. Both episodes are adaptations of TMNT #2, so saying that the Mouser two-parter takes cues from "A Thing About Rats" would be akin to saying "The Shredder Strikes Back" takes cues from the original movie.