Incorrect Reading on Deceleration

If there is no voltage, check EGR control switch. With speed sensor jumped and engine at idle, remove vacuum hose at EGR control switch and check for vacuum. If vacuum is available, reconnect hose and check for voltage at EGR control solenoid valve A. If there is no voltage, replace EGR control switch and retest.
If vacuum and voltage are available at same time, replace EGR control solenoid valve A.

Fig 1: Blocking EGR At Control Box

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Fig 2: Honda Exhaust Gas Recirculation System (California Accord & Prelude with Man. Trans.)

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Fig 3: Honda Exhaust Gas Recirculation System (All Models, Federal)

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Fig 4: Honda Exhaust Gas Recirculation System (California Civic)

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Fig 5: Honda Exhaust Gas Recirculation System (California Accord & Prelude with Auto. Trans.)

Courtesy of AMERICAN HONDA MOTOR CO., INC.