Here is a kicker. I bought my Catera and I thought it was a 1998 model. The title said it was '98 so I just assumed it was. However, I recently did a VIN check and it comes back saying my car is a 1999. So I was excited that it was a newer model. However, when I purchased a new O2 sensor (for a 1999 model) the plug is wrong. I checked online and the plug I need matches the 1998 model. Whats going on? Which would be more accurate? Obviously, my car has 1998 parts (my oil filter and O2 sensors are) but the VIN says its a 1999. Any ideas??