I have a 99 Catera and am needing to change the oil in it since I just got it. I don't have the owners manual and it doesn't say on the cap what weight to use. My plan is to use Mobil 1 synthetic. Also, I went to get an oil filter at the parts store and the guy gave me this weird filter that looks like it's for a tractor. I'm sure it's probably the right one but is it a canister that you take off and then replace the element on the inside and then put it back on?