I bought an 05 tahoe Lt w 200k miles v8 5.3. Had it 3 weeks now n getting low oil pressure read out. When I start it, if the engine is not already warm, I get alarm so I have to gas it to keep pressure. Once vehicle is warm it doesn't have issue but hovers just below or at 40. I'm almost certain it isn't sensor. I want to replace oil sending tube seal. My question is, if I have the money even though I don't want to spend it, should I replace pump n sender as well since I've already dropped oil pan?