SEPANG, Malaysia - Red Bull team principal Christian Horner on Friday (Mar 28) called for the removal of fuel-flow sensors after the team suffered more issues with the system during practice for the 2014 Malaysian F1 GP.Horner's new driver Daniel Ricciardo crossed the line second in the season-opening Melbourne GP a fortnight earlier, only to be disqualified for exceeding the flow limit of 100kg/hour.Red Bull queried the accuracy of the meter and has appealed but the hearing is not due until April 14 2014.PROBLEMS FOR OTHER DRIVERSHorner said he would talk with International Automobile Federation technical delegate Charlie Whiting before Sunday's (Mar 30) race in Sepang after Ricciardo's sensor failed and was replaced on Friday.He added that he knew of other drivers who had experienced problems with the system and said: "If we don't (get synchronised readings) we will find ourselves in an awkward situation but one we will try to work on with the federation but we will find ourselves in the same dilemma as in Melbourne."We need a better way to measue and monitor fuel flow or it should be got rid of and have 100kg for the race - and that's it."Personally, I think it would be easier to get rid of it."Allowing unregulated fuel-flow could open the door to sophisticated engine-mapping with teams seeking to extract more performance.The federation attempted to ease the confusion around the flow system by holding a briefing to explain how it worked and the regulations applied, suggesting it had no interest in modifying or removing it.THIRD REPLACEMENTFuel-flow sensors were not the only problem for Red Bull: the team's champion driver Sebastian Vettel required a new electronic power-control unit for Saturday qualifying and Sunday's race.It will be his third replacement with only five changes permitted over the 19-race season before grid penalties are imposed.Four-times champion Vettel finished Friday's second practice session third-quickest with Ricciardo seventh to give the team hope that it could win points to get off the mark in Malaysia.Vettel said after finishing 0.61sec behind Mercedes' Nico Rosberg: "I think we had a good day. Friday timings are not the most important thing in the world but it's good to be up there and in range of the top guys. "There are still things to solve on the software side and programming but that's the way it is. We have to learn a lot but, all in all, I'm quite happy."