407 1.6 Comfort trip computer instant fuel.

Hello friends,

Last week, I joined the 2008 model 407 1.6 HDI comfort. Instant fuel figures show very high values on the vehicle's road computer. For example: While the 3rd Gear is going without stepping on gas, a silly figure like 999 appears, it shows very high values such as 55, 35 etc. What would be the reason. How can I find a solution? Could there be a software problem on the trip computer, if so, where should I take the vehicle out of service.

Also, when some of the tape keys are hardened, it turns out very heavy, do you have any suggestions to return to normal?

Thank you very much in advance for your answers.