When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
On that note, definitely inspect the No. 2. plug on the passenger side of the car next to the firewall. If the previous owner/mech. balked at changing ANY plug, it'd be that one. (Yup, it's that big a ****!)
If that one's in good shape (and they're non-AC/Delco platinum) you might be good to go on achieving the maximum service life of 100,000 miles.