chillywilly7g

Hello to all, this is prety much my first thread here in the Org.
Well, I own a '02 Max SE, Auto with 38,XXX miles.
I just cleaned my manifold with some Valvoline Synthetic Intake and Throttle body cleaner. my manifold was black with carbon. I ran the engine and really got the cleaner in the intake. now it's all nice and clean.
Well, after all the cleaning I did, the engine seemed more responsive to my foot commands but there's a problem now.....
While i drive, eveything is ok, but when I start slowing down, the engine seems to surge just before it revs below 1000 rpms, goes up to about 1250 and goes down and at 1000 it does it again. While it does that it also seems to SHIFT downward from fourth gear to first, like if i was manually downshifting the gate from D to 1 right at 1000 rpms. i'm not sure if i did something wrong or if i'm missing something to fix this situation. Also, when I start up the car, the engine rises fast to start, but stays at about 1500 for about 5 or more seconds before lowering to idle speeds. If someone can help me with this please? I'd greatly appreciate it. I tried to look around to see if there was any other post similar to this but no luck, so I'm sorry if i post a similar one around.
I did reset the ECU beacuse since i ran the engine without the intake ( Injen CAI ) it gave the "Check Engine Soon" light. After the cleaning, i reinstalled the intake and the ECU reset turned the light off. I'm not sure if there's any other procedure to do if I missed any?
i'd apreciate any feedback about this. Thank you.