Hey all. I'm looking at a '97 2.5TL w/ the Premium Package. It's got about 90,000 miles. Everything sounds good, but the seller says that the "check engine" light - the mechanic said that one of the electrical sensors is old and needs to be replaced (supposedly $200-$300).

Does anyone have any idea what the underlying problem might be? Could it indicate that there is a larger problem he's not telling me about?

Also, one last question: do you actually have to put premium gas in it? I understand the differences between regular and premium (higher temp before combustion), but I also know that luxury cars will often call for premium gas just to make the car seem more luxurious. The 2.5L engine only has a compression ratio of 9.6, which is exactly the same as that on my truck (which runs just fine on regular). So does anyone actually get engine ping when using regular?

Thanks for the help!