Hi all, recently bought an 01 dts with 45k mi. I was reading the manual book and found that this car can run on 87 octane. I went to the pump and gave it 87 and about half a tank later the service engine light came on. Do any of you think it amy be due to that? Ive refueled with 89 and 93 but hasnt gone away. Also is there any way to check for codes on these cars like in mid 90's models? Thanks for the help in advace.