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1997 993tt Boost Pressure Reading

Electrical and Electronic

Vehicle Information: Year: 1997; Body Type: Coupe; Total Mileage: 7800;

The boost pressure reading on the car goes to 0.8 bar for a fraction of a second as the ignition key is first turned to the right, then it drops to 0.2 bar until the engine is cranked, at which time it goes to 0.0 bar. While the engine is running, the readings seem normal.The only exception was during one trip, the reading appeared to "stick" on 0.2 bar for maybe 30 seconds, even with zero throttle. I have been monitoring the reading carefully and this has not happened again. (That one incident was a month or so ago.)The electrical connector is snug. Because of that one incident and a little corrosion on the outside of the boost sensor, the boost pressure sensor was replaced, but the pattern of readings as the car is started continues. (The sequence of readings is very consistent and repeatable.)Could this seqence of 0.8 to 0.2 to 0.0 bar be some sort of automatic calibration or initialization being done by the computer, or do I have a gremlin in the system?Boost readings seem normal while driving. At full throttle it reads 0.7 or 0.8 bar, at medium throttle it is 0.2 to 0.5 bar. If I am at light throttle...low speeds, traffic, steady highway driving etc., it reads 0.0 bar. A very competent and experienced Porsche technician has looked at it and it seems normal to him also.Thanks!Car Prep: ModifiedModifications: added Turbo S oil cooler, euro suspension,strut tower braceTotal Mileage: 7800Car Use: Combination Street and Track

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