Transmission Question

I've got a 99 Grand Am Gt and it's been having some problems with the transmission lately when it gets hot. So I thought it might not be a bad idea to change the transmission fluid, maybe to synthetic fluid, but I've read on here before that flushing out the transmission always leads to trouble. So I just wanted to make sure that just changing the fluid wouldn't cause a worse problem then I already have. Alright thanks for the input.

Also it was posted on a previous post of mine about this problem and others that it all could be due to a clogged catalytic converter so I just wanted to see if there was any way to check that without having to take it to a muffler shop. Also if it is clogged will I need a new converter or can it be unclogged.

To answer your first question changing the transmission fluid and filter is not flushing the transmission and will not hurt anything. Actually it is recommended every 30K miles. You don't say what the problem is but if it is fluid and filter related then this should help. You may want to also add a can of Seafoam additive to the fluid. It will clean any sticking solenoids and help the tranny shift better.

As for your second question, you can test the cat without dropping it. You may want to search the forum as it has been posted several times. I can't tell you from memory how to do it. If the cat proves bad you will need to replace it for best performance.