Oil pressure issue 2001 gx

[Bigal]

Recently bought another gx with 60k on the clock, insurance is way too high on a wrx so this will do for now! Haven't had a chance to test what pressure it's actually running at but on idle the oil light is on, and throughout the rev range it's very tappety. changed the oil and it's made no difference, next step was to remove the sump and check the pick up for damage or blockages but that's fine. Not too sure what to check next. Any advice will be much appreciated!
Alex

[asperformance]

would personally get an oil pressure reading first, you may well be chasing a damaged sensor or it may be a goosed/jammed oil pump??

[Bigal]

I forgot to menchen that I changed the pressure sensor today, I'll try and get a reading asap. Only thing being I'm not sure how long it's been driven for with the cams chattering like they are! Really hoping for no internal damage but from the way it sounds it might be too late.