My 01 Firebird TA is a automatic and when I put it in regular drive and floor it it shifts down but it seems like its not shifting into the right gear. As in it wont accelerate as quickly as if i were to do it myself. I've looked into my Haynes manual and it doesn't have a throttle cable. I'm pretty new with the LS1 so take it easy on me

 

I would try a new TPS .... they are cheap and easy to change. Took me about 10 minutes maybe less. Think I got one for about 20.00. Fixed the weird trans shifting for me.

 

In my experience the 4L60e transmission found in these cars only drop from 4th to 3rd, when they could really go to 2nd depending on speed of course. You will probably be better off shifting down yourself in this case. If you have the money get a shift kit or send it to your transmission shop.

 

What gear is in it? 3.23's should drop from 60mph or less into 2nd gear and pull like hell. A good tune will fix the issues your having.