Power plant piece in HeartGold

Hi guys,
i'm having kinda problem with finding the power plant piece in HeartGold.
I've done everything that I think I must do before I can get it: defeated Misty, defeated and followed the rocket guy. But I still can find that piece in the gym of cerulean city...
Is there something I may have missed?Thx

Did you press a in the middle water?

Pretty sure it's somewhere in the rescue tubes (Round things) on the left side of the gym. Check near middle. (Also if you check on top or on bottom of tube it matters, forgot which but when I tried top it didn't work but when I tried bottom side of the pile of tubes I got it(It might also be different for the piles of tubes because I did it on Soul Silver))

yep its on the top left near the rescue tubes

Ok i'll see.. But you can't see it on your itemfinder can you??Post Merge: [time]1267457361[/time]
Thx so much :p I finally found it

First you have to talk to the guy in the power plant(owner) then you go back to the gym and u will see a rocket grunt and follow him to the bridge nugget, defeat him there and u find the part on the life tubes at the left far end of the gym.