Pull the codes for sure... BUT CHECK THIS...
I purchased my 03 STS back in Late July... Was driving about a month later and hit a bump and BAM!!! Felt like the frame hit the ground in the front!!! That was just WRONG!!!! Well, I went to the dealer and the Tech said, he did see some leaking, so they replaced both front struts. Have NEVER had the car hit a bump that hard since... And I've run it hard, even on the streets in Newark and it was smooth. SO, Although they are supposed to last over 100K miles, YA NEVER KNOW!!!
BTW, When I bought my car it was a "Certified Pre-Owned" HA!!! But the dealer did indicate the car probably sat for a while with no use, which can cause issues, especially with front struts. Just food for thought!