Suspension problems STS?
 

It seems like my 2003 STS with 41,000 easy miles has started riding like a truck. I don't recall how long this has been going on, but I first noticed it shortly before or sometime after my last service which included an oil change and tire rotation 3 months ago. I did receive a "service suspension system" or similar message a year or so ago, but took no action because the ride seemed normal.
Pushing down on the bumpers with force seems to produce a normal response, warm tire pressure is currently 34psi all around, and the car tracks straight.....just bumpy as hell on the road. There are no unusual sounds. I have pulled and cleared the codes several times mainly to squelch the "service engine soon" light. There are currently no codes.
My brother-in-law's 1998 STS with 70K miles and no suspension work still rides like a dream.
Any suggestions would be greatly appreciated.

1998 Seville STS
Wavy driving; loose feel; struts gone bad :eek:
"Service Suspension System"
Purchased the Arnott McPherson Struts with dummy sensors $299 free shipping
Ride is dramatic improvement
Still the DIC message "Service Suspension System"

Not to go off topic with your question/s. Mine is a 1994 and I would get the Service Suspension System also. When I checked the codes after learning how to do this.....OFF/RED buttons I got a crap load of codes. Funny thing is, when I turned the car off and restarted it the Service Suspension System display vanished. I'm not even sure if I got a question here or not.......but I guess I'm going to ask now since this is all new to me (the car; just purchased it). Did I just reset the Suspension code when I went through the procedure of displaying codes; also, alot of the codes had the word "HISTORY" after them, what does this mean; and finally......I got a display of "PCM?" What is this???
Sorry, I didn't mean to ask questions on my vehicle and not even answer yours. I do not have an answer. All these displays are new to me, just got the car this week. Wasn't sure if I should start a new thread or just continue off of yours on somewhat of the same topic.

Ok, scratch that one.........the "Service Ride Control" never did reset as I thought it did. I still do have a crap load of codes though. As I said, this car I just purchased and is new to me with all these displays and codes. I will do a search on here along with reading and see if I can come up with answers on how to troubleshoot etc.
thnx.!

Thanks for the tip!

MC pherson struts are really very reliable and they'd be running all the way it your road for a long period of time as compared with other ones.