This procedure covers removal and installation of the front exhaust pipe (downpipe) on a 2016-2024 Hyundai Tucson with the 2.5L I4 engine and AWD, including oxygen sensor handling and exhaust flange connections.

Warnings

Tools required

Parts

• Front exhaust pipe assembly × 1 — Use OEM specification
• Exhaust gasket (manifold to front pipe) × 1 — Use OEM specification
• Exhaust gasket (front pipe to catalytic converter) × 1 — Use OEM specification
• Exhaust flange bolts × 4 — Use OEM specification
• Exhaust flange nuts × 2 — Use OEM specification

Preparation

1. Park vehicle on level surface and allow exhaust system to cool completely (minimum 2 hours after last operation).
2. Apply wheel chocks to rear wheels.
3. Raise front of vehicle and support securely on jack stands at manufacturer-specified lift points.
4. Spray all exhaust fasteners with penetrating oil and allow to soak for 15-30 minutes minimum.
5. Remove any underbody panels or heat shields blocking access to front exhaust pipe (typically secured with 10mm bolts).

Procedure

1. 1

   Disconnect oxygen sensor electrical connector
   Locate the upstream oxygen sensor connector mounted to the body or harness near the engine. Press the release tab and carefully disconnect the electrical connector. Inspect connector for corrosion or damage.
2. 2

   Remove upstream oxygen sensor
   Using a 22mm oxygen sensor socket, carefully unthread the upstream oxygen sensor from the front exhaust pipe. Turn counterclockwise with steady pressure to avoid stripping threads. If sensor is seized, apply additional penetrating oil and allow to soak, then retry with gentle heat if necessary. Set sensor aside if reusing.
   ⚠Do not use excessive force on oxygen sensor. Damaged threads in the exhaust pipe may require pipe replacement.
3. 3

   Remove heat shield mounting bolts
   Remove any heat shield bolts securing shields to the front pipe or surrounding area using a 10mm socket. Heat shields may be present above or below the pipe depending on configuration. Set shields and hardware aside.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
4. 4

   Disconnect front pipe from exhaust manifold
   Locate the two-bolt flange connection between the exhaust manifold and front pipe at the engine. Using a 14mm socket, remove both exhaust flange bolts. Support the front pipe weight as you remove the final fastener. Separate the flange connection and remove the old gasket.
   ⚠Flange bolts may be severely corroded. If bolts break, replacement studs or extraction may be required.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
5. 5

   Disconnect front pipe from catalytic converter
   Move to the rear flange connection where the front pipe connects to the catalytic converter or mid-pipe. Using a 14mm socket, remove the flange bolts or nuts (typically 2-3 fasteners). Support the pipe as you remove the final fastener.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
6. 6

   Release exhaust hangers
   Locate the rubber exhaust hangers supporting the front pipe (typically 1-2 hangers). Using an exhaust hanger tool or pry bar, carefully work the metal hooks out of the rubber isolators. Spray with soapy water if needed to ease removal. Avoid tearing the rubber isolators.
7. 7

   Remove front exhaust pipe
   With all connections released, carefully maneuver the front exhaust pipe downward and rearward to clear the vehicle. The pipe may need to be rotated or angled to clear subframe components and the AWD driveshaft. Inspect pipe for damage or excessive corrosion.
8. 8

   Clean mating surfaces
   Using a wire brush or gasket scraper, thoroughly clean all exhaust flange mating surfaces at the manifold outlet and catalytic converter inlet. Remove all traces of old gasket material, carbon deposits, and corrosion. Inspect flange faces for warping or damage.
9. 9

   Install new front exhaust pipe
   Position new exhaust gaskets at both flange connections (manifold and catalytic converter). Carefully maneuver the new front pipe into position, aligning with both flanges. Insert the pipe hooks into the rubber exhaust hangers. Start all flange bolts/nuts by hand before tightening any.
   ℹ️Ensure gaskets are properly seated before starting fasteners. Misaligned gaskets will cause exhaust leaks.
10. 10

    Torque manifold flange connection
    Apply anti-seize compound to the threads of the exhaust flange bolts connecting to the manifold. Using a torque wrench, tighten the bolts in an alternating pattern (cross-pattern) to the specified torque of 45.0 Nm (33.0 lb-ft). Verify both bolts are evenly tightened.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
11. 11

    Torque catalytic converter flange connection
    Using a torque wrench, tighten the flange bolts/nuts connecting the front pipe to the catalytic converter in an alternating pattern to the specified torque of 47.0 Nm (35.0 lb-ft). Double-check alignment of pipe before final tightening.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
12. 12

    Install oxygen sensor
    Apply a light coat of anti-seize compound to the oxygen sensor threads only (do not contaminate sensor tip). Thread the oxygen sensor into the front pipe by hand to avoid cross-threading. Using a 22mm oxygen sensor socket and torque wrench, tighten to 45.0 Nm (33.0 lb-ft).
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
13. 13

    Reconnect oxygen sensor and reinstall heat shields
    Connect the oxygen sensor electrical connector, ensuring it clicks securely into place. Reinstall any heat shields removed earlier and torque mounting bolts to 10.0 Nm (7.0 lb-ft). Verify connector routing is clear of hot exhaust components.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Reinstall any underbody panels or covers removed during preparation.
2. Lower vehicle from jack stands safely.
3. Visually inspect all connections and ensure no tools or parts were left in the engine bay.

Verification

• Start engine and allow to idle. Listen carefully for any exhaust leaks at both flange connections and oxygen sensor.
• Check for visible exhaust smoke or fumes escaping from connections while engine is running.
• Rev engine to 2000-2500 RPM and recheck for leaks under increased exhaust pressure.
• Verify no Check Engine Light illuminates and oxygen sensor is reading properly (may require scan tool verification).
• After 10-15 minutes of operation, re-inspect all flange bolts for tightness and check for any signs of exhaust leakage or discoloration around connections.

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