I have been reading threads for hours and I think I am more confused than ever! LOL I know there has been alot of posts about the oil pressure dropping to 0 when a car idles and I have read all the responses about the oil sending unit. I also read that cars with a light have an oil pressure switch and cars with a gauge have an oil pressure sending unit. My trailblazer which is a 2002 LS has a light and a gauge so Im not sure which one it is? Also, my car was not stalling or making noises when the pressure would drop, does that mean it is more likly to be the sending unit/switch? I checked my oil and it did not appear to be low....I read that you can disconnet the unit/switch and then start your car and if the gauge stays at a normal pressure then it is probably the unit/switch failing. I can't even find the unit/switch in my car IDK where to even look. I know everyone is saying its by the oil filter but I thought the oil filter was under the hood not under the car itself...I don't know much about cars which Im sure is obvious but any insight on this would be truly appreciated!