I have a 1997 Porsche Boxster. It has had 2 fuel pump relay failures in 1 month. What causes this so soon?

Could be several reasons for this, first would be a faulty first replacement part, or you could be having some sort of grounding or voltage issue that is causing the repeted failure. if you had the part replaced at a reliable shop it should be warrentied for at least 30 days, l would hold them to it and also have them check the voltage and check for any ground fault issues.

We had the same thing with our Volvo. It was caused by a bad oxygen sensor. l do not know for sure but maybe this will help.

l would check to see if there is an updated part. On my '91 911 (964) there was a problem with the DME/Fuel Pump Relay. It would open while l was driving and l would pull over. After a short wait, the car would start. Also you might check the amps draw is on the pump. l know the amperage goes up as the pump get toward the end of its life.

An amperage draw test & voltage drop test at the pump would be required to accurately ascertain the reason the relay is so short lived..only poor supply(poor battery voltage to relay..terminal 30) to the relay or high amperage draw through it (bad pump) would cause the rapid failure.as long as u r using a QUALITY relay..install new relay & check supply to relay & voltage at pump..should be very close.if not move on to amperage test.in-line.. if u have a DVOM that will support this test..if not find a GOOD tech to help out.