Hi, I'm Robb from the mid-Michigan area and I'm thinking about buying my brothers 99' Catera. It has some issues. The one that annoys me the most is the speedometer is off. The only time it's right is around 55mph. If I want to go 30mph the speedo reads 40mph. When above 55mph the speedo is off the other way. If the speedo reads 65mph, I'm actually going about 74mph:hmm:. The gas gauge doesn't read right either. I did multiple searches on hear for this issue and came up with nothing. Thanx in advance for any help you guys can give me.