Timing question

quick question, my header on the left side vibrates on my floorboard, i realize this is probably causing the PCM to pull timing, my question is how long will the PCM keep the timing down? Does it return the timing to normal immediately or does it retain the "retard" for a minute?
reason im asking is I pulled my trans out to seal the front pump, when i put everything back together the Y-pipe at the collector is vibrating against the floorboard....pretty damn loud i might add...driving the car back home I feel a noticeable lack of power. When i drove it to the shop its running real nice like always, get to the shop pull trans, put it all back together...have banging noise from headers and car is weak...:think:

thank you for any advice

If the computer thinks there is knock it will pull timing immediately and slowly goes back to normal which is not that long really. I had my headers hitting something under the car and just adjusted them so it stopped. I was prepared to put something in between that would not burn to stop the noise. My left over plug wire heat protectors that are made of fabric would have worked perfect.

what did u do to clear the header, i really dont wanna bend the y-pipe anymore than it already is, did u bend the floor bracing up? is that ok to do? i just dont wanna f!@# something up ya know. Im just really bugged that the car feels weaker, not sure if its me over reacting or if its really weak...ill find out Friday at the track if its running weak (course im gonna fix the header issue). But yeah what did u do to "clear" it? I dont want to break the welds on the header by bending it down more.