I have a 90 XJ with the 4.0 and i developed a bad oil leak, i beleive its coming from my oil pressure sensor right above the filter. Is there just a gasket to replace or is it the entire sensor you replace?? And also ive heard oil can leak out by the distributor, is that a gasket as well. Id like to knock out all 3 while im there, the oil pressure sensor, dizzy and oil filter adapter just to be safe. Any help is much appreciated. Thanks!