Frankie, if the pressure cells (all 5 of them, one for each shocks and a central one) have not been changed for more than 4 years or 60K miles, it is due. I changed mine 3.5 years ago and 30K miles, and they are readied for new ones again!!! It will cost about $1000 for this.
By the way I use 225/50-16 on my car. I have a set of AVS Sport and Pilot XGT-Z4 both mounted on 8 inch wide wheels and they both ride fine but not as good as 14 or 15 inchers. Good luck.