I am new to the GP world. I used to have a park ave with the 3.8 s/c but it spun a rod bearing. So im taking another round with an 04 Grand Prix GT (couldnt afford a gtp) I bought it for $6200 from a Wilde Toyota which as a HUGE used car collection. It has 91,000 miles on it and came up to Wisconsin from North Carolina in 2008. Its got 2 blemishes on the outside but i figured it was a good deal. However, i have noticed a little bit of a clanky/popping noise from what sounds like the exhaust system when revved and is cold or has been cooling for a while. When the car is hot it will not make the noise. I am worried it is coming from the Catalytic converter. Is this something i need to be concerned about or is just hot air flowing through a cold exhaust? keep in mind i am in Wisconsin and right now it is getting down to the low 40's and high 30's.
