Hello All! After 3 weeks of work (on and off) I finally have my hoe put back together from doing the oil pump / pick up tube o-ring! That pesky life thing kept getting in the way. Found out my wife is pregnant with our second, Super excited! But that also brought on insane morning sickness, so that pumped the brakes on me spending time in the garage wrenching on this thing... Down to business... I put in an oem replacement oil pump, changed the O-ring, cleaned the sh*t out of stuff while I was in there. Result: I fixed my leaking from everywhere oil pan gasket and my oil pressure definitely indicates higher about 40psi crusing on the freeway around 2k rpm. Yayy! And then the tahoe dealt the punch to the throat. My problem continues → engine at operating temperature, come to a stop at a light, oil pressure drops to ZERO and warning light comes on the dash to "Check Engine Oil Pressure" I'm pretty sure my dad changed the oil pressure sending unti before I got the car, and he reported that it didn't change the problem, however he didn't know about the screen under the unit until after he was done. Could that screen be the problem? Could it be the sendign unit? Thoughts? Thanks!