Sender replaced under diesel rap extended warranty some ridiculous price like $180 or something but curred the no oil pressure at idle problem,also had an oil leak which they suspect being the vacuum pump,something like $800 what a rip off but for $50 I guess it,s a bargain. FYI the 98 12 valves have the same electrical plug as the 24 valve trucks which makes them so high but I think napa can help for under $30 echlin Part # op-6189.