Manifold Absolute Pressure Sensor

Replace the Manifold Absolute Pressure (MAP) sensor on a 1992 Dodge Viper 8.0L V10 engine. The MAP sensor monitors intake manifold pressure for engine management calculations.

Warnings

Tools required

Parts

• MAP sensor × 1 — Mopar 4686684 or equivalent
• MAP sensor O-ring or gasket (if separate) × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery cable and wait 2 minutes to allow airbag system capacitors to discharge
3. Locate the MAP sensor on the intake plenum (typically mounted on the driver's side of the intake manifold near the throttle body area)
4. Have clean shop towels ready to cover the sensor opening during replacement to prevent foreign material from entering the intake manifold

Procedure

1. 1

   Access MAP Sensor
   Open the hood and locate the MAP sensor on the intake manifold. The sensor is typically mounted on the driver's side of the intake plenum near the throttle body. It will have a single electrical connector and a vacuum reference port connection to the manifold. Verify you have clear access to the sensor mounting fasteners and electrical connector.
2. 2

   Disconnect Electrical Connector
   Locate the electrical connector on the MAP sensor body. Press the locking tab or release mechanism on the connector and carefully pull the connector straight off the sensor. Do not pull on the wiring harness itself. If the connector is stubborn, gently work a small flat-blade screwdriver under the locking tab while applying light outward pressure on the connector body.
3. 3

   Remove MAP Sensor Fasteners
   Remove the MAP sensor mounting fastener(s) securing the sensor to the intake manifold using the appropriate driver (verify count and drive type against factory service information for the 1992 Viper). Keep these fasteners in a clean location as they may be reused if in good condition and not corroded.
   Torque spec

   MAP Sensor Screws3 Nm (2 lb-ft)
4. 4

   Remove MAP Sensor from Manifold
   Carefully pull the MAP sensor straight out of the intake manifold. There may be an O-ring seal that provides both sealing and retention. If the sensor is stuck, gently twist while pulling to break the seal. Do not pry against the sensor body or manifold surfaces. Immediately cover the open port in the intake manifold with a clean shop towel to prevent debris from entering.
5. 5

   Inspect Mounting Port and O-ring
   Remove the shop towel temporarily and inspect the MAP sensor mounting port in the intake manifold. Look for debris, damage, or corrosion. Clean the mounting surface with a shop towel if necessary. Inspect the old sensor's O-ring or gasket. If the O-ring remained in the manifold port, carefully extract it with a pick or small screwdriver. Check whether the new sensor includes a new O-ring; if not, the old one may be reusable if undamaged. Replace the shop towel covering the port.
6. 6

   Prepare New MAP Sensor
   Remove the new MAP sensor from packaging and inspect it for shipping damage. If the sensor includes a new O-ring or gasket, install it onto the sensor body according to the manufacturer's instructions. If reusing the old O-ring, ensure it is clean and free of cracks or compression damage. Lightly lubricate the O-ring with clean engine oil if needed to ease installation.
7. 7

   Install New MAP Sensor
   Remove the shop towel from the manifold port. Align the new MAP sensor with the mounting port, ensuring the vacuum reference port on the sensor lines up correctly with the manifold opening. Carefully push the sensor straight into the manifold until it seats fully against the mounting surface. The O-ring should compress evenly.
   ⚠Ensure the sensor is fully seated before installing fasteners. A partially seated sensor can result in vacuum leaks and incorrect readings.
8. 8

   Install and Torque MAP Sensor Fasteners
   Install the 2 MAP sensor mounting screws finger-tight, ensuring they thread smoothly without cross-threading. Using a torque wrench, tighten the screws to approximately 3.0 Nm (2.2 lb-ft) in a criss-cross pattern (alternate between fasteners), or to the factory-specified value if available. Do not exceed the specified torque as the sensor housing or manifold boss can crack.
   Torque spec

   MAP Sensor Screws3 Nm (2 lb-ft)
9. 9

   Reconnect Electrical Connector
   Align the electrical connector with the MAP sensor terminals and push it firmly onto the sensor until you hear or feel the locking tab click into place. Gently tug on the connector body (not the wires) to verify it is fully locked. If available, spray a small amount of electrical contact cleaner into the connector before mating to ensure good electrical contact.
10. 10

    Reconnect Battery and Clear Codes
    Reconnect the negative battery cable and tighten the terminal clamp securely. If a diagnostic trouble code (DTC) was set for the MAP sensor before replacement, it may be necessary to clear codes using a scan tool, or clear stored codes by disconnecting the negative battery cable for a period, or by using a compatible scan tool (DRB-type) appropriate for this pre-OBD2 Chrysler system.

Reassembly

1. No additional reassembly required beyond the steps outlined above

Verification

• Start the engine and allow it to idle. Listen for any vacuum leaks (hissing sounds) around the MAP sensor installation area
• Verify the engine idles smoothly without rough running, stalling, or abnormal idle speed fluctuations
• If a scan tool is available, verify the MAP sensor is reading appropriate manifold pressure values (typically 20-22 inHg at idle at sea level, closer to atmospheric pressure around 29-30 inHg with engine off and ignition on)
• Test drive the vehicle and confirm normal acceleration, no hesitation, and no check engine light illumination
• Re-check for diagnostic trouble codes after test drive to ensure no MAP sensor-related codes have returned

Related trouble codes on this vehicle

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