This procedure covers the replacement of a catalytic converter with a universal unit on a 2016-2024 Hyundai Tucson with the 2.5L I4 AWD engine, including removal of exhaust components, oxygen sensors, and proper installation with new hardware.

Warnings

Tools required

Parts

• Universal catalytic converter (EPA compliant) × 1 — Verify diameter matches OEM (typically 2.25")
• Exhaust flange gasket × 2 — Use OEM specification
• Exhaust adapter pipes (if required) × 1 — Match universal converter inlet/outlet
• Band clamps or welding sleeves × 2 — 2.25" diameter stainless steel
• Oxygen sensor (upstream if damaged) × 1 — 39210-2GTA0 or equivalent
• Oxygen sensor (downstream if damaged) × 1 — 39210-2GTA1 or equivalent
• Exhaust flange bolts × 8 — M10x1.25 stainless steel
• Exhaust hanger isolators (if worn) × 2 — Use OEM specification

Preparation

1. Park vehicle on level ground and allow exhaust system to cool completely (minimum 1 hour after last operation)
2. Chock rear wheels securely
3. Raise front of vehicle and support on jack stands at manufacturer-designated lift points
4. Spray all exhaust flange bolts, oxygen sensor threads, and hanger bolts with penetrating oil and allow 15-20 minutes to soak
5. Disconnect negative battery terminal to prevent oxygen sensor fault codes during removal
6. Remove any belly pans or skid plates blocking access to catalytic converter area
7. Identify catalytic converter location (mid-pipe position between exhaust manifold and muffler on AWD models)

Procedure

1. 1

   Remove heat shields
   Locate heat shields covering the catalytic converter. Remove heat shield mounting bolts using 10mm socket. Set heat shields aside for reinstallation. Inspect heat shields for damage or excessive rust; replace if compromised.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
2. 2

   Disconnect upstream oxygen sensor
   Locate upstream (pre-catalyst) oxygen sensor on the inlet pipe. Disconnect electrical connector by pressing release tab. Using oxygen sensor socket, carefully unthread sensor from exhaust pipe in counterclockwise direction. If sensor is seized, apply heat with propane torch to surrounding bung (not sensor itself) for 30 seconds, then retry removal. Set sensor aside if reusing.
   ⚠Do not allow oxygen sensor to hang by its wiring. Support sensor body to prevent wire damage.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
3. 3

   Disconnect downstream oxygen sensor
   Locate downstream (post-catalyst) oxygen sensor on the outlet pipe. Disconnect electrical connector. Using oxygen sensor socket, remove sensor from exhaust pipe following same procedure as upstream sensor. Inspect sensor condition and replace if contaminated or damaged.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
4. 4

   Remove upstream exhaust flange connection
   Locate flange connection between exhaust manifold downpipe and catalytic converter inlet. Support catalytic converter with jack stand or helper. Remove flange bolts using 14mm socket, working in crisscross pattern to prevent binding. Separate flange connection and remove old gasket. Inspect flange faces for warping or damage.
   Torque spec

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

   Remove hanger supports
   Identify rubber exhaust hangers supporting the catalytic converter assembly. Use pry bar or spray hangers with soapy water to ease removal. Disconnect hangers by sliding rubber isolators off metal hooks. Note hanger positions for reassembly.
   Torque spec

   Hanger Bolts20 Nm (15 lb-ft)
6. 6

   Remove downstream exhaust flange connection
   Locate flange connection between catalytic converter outlet and mid-pipe or rear exhaust section. Remove flange bolts in crisscross pattern. Lower and remove catalytic converter assembly from vehicle. Inspect exhaust system alignment and condition of remaining pipes.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
7. 7

   Measure and prepare universal converter
   Measure removed OEM catalytic converter inlet and outlet pipe diameters and overall length. Compare with universal converter dimensions. Most 2.5L Tucson applications use approximately 2.25" diameter pipes. Determine if adapter pipes or reducer sleeves are needed. Test-fit universal converter in vehicle to verify clearance with chassis, driveshaft, and heat-sensitive components.
   ℹ️Universal converters typically require 2-4 inches of straight pipe on each side for proper clamping or welding.
8. 8

   Cut and prepare exhaust pipes
   Mark cutting locations on existing exhaust pipes to accommodate universal converter length. Account for pipe overlap inside clamp sleeves (typically 1.5-2 inches per side). Use reciprocating saw with metal blade or exhaust pipe cutter to make clean, square cuts. Deburr cut edges with file or grinder. Clean pipe ends with wire brush to ensure proper sealing surface.
   ⚠Wear eye protection during cutting operations. Metal shavings can cause serious eye injury.
9. 9

   Install oxygen sensor bungs
   If universal converter does not have pre-installed oxygen sensor bungs, weld bungs in correct positions to match OEM sensor locations. Upstream sensor typically positioned 6-8 inches from converter inlet; downstream sensor 6-8 inches from outlet. Ensure bungs are angled to prevent sensor wire strain. Clean bung threads with tap to remove welding debris.
   ⚠️Welding operations require proper ventilation and fire safety precautions. Disconnect battery and protect fuel lines from sparks.
10. 10

    Install universal catalytic converter
    Position universal converter in exhaust system. Slide inlet adapter pipe onto upstream exhaust section, ensuring minimum 1.5" overlap. Slide outlet adapter pipe onto downstream section. Align converter to maintain proper ground clearance (minimum 10 inches) and ensure no contact with chassis, driveshaft, or fuel lines. Hand-tighten band clamps but do not fully torque yet.
    ℹ️Converter substrate material is fragile. Do not strike or drop converter during installation.
11. 11

    Reconnect exhaust hangers
    Reattach exhaust system to rubber hanger isolators. Use soapy water to lubricate rubber and ease installation. Ensure exhaust system is centered in chassis tunnel with even clearance on all sides. Verify no contact points with body, suspension, or drivetrain components throughout full suspension travel.
    Torque spec

    Hanger Bolts20 Nm (15 lb-ft)
12. 12

    Tighten exhaust clamps and connections
    Starting from upstream end, torque band clamps to manufacturer specification (typically 40-50 Nm for 2.25" clamps). Work toward downstream end. If using flanged connections instead of clamps, install new gaskets with high-temperature sealant, then torque flange bolts in crisscross pattern. Double-check all connection points for proper alignment and sealing.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
13. 13

    Install oxygen sensors
    Apply thin coat of anti-seize compound to oxygen sensor threads only (avoid sensor tip contamination). Hand-thread upstream oxygen sensor into bung until finger-tight. Torque sensor to specification using oxygen sensor socket. Repeat process for downstream sensor. Route sensor wiring away from hot exhaust components and secure with OEM clips or heat-resistant zip ties. Reconnect electrical connectors ensuring positive click engagement.
    ⚠Never apply anti-seize to oxygen sensor tip or contamination will cause false readings and sensor failure.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
14. 14

    Reinstall heat shields
    Position heat shields over catalytic converter and mounting locations. Install heat shield bolts and torque to specification. Ensure heat shields do not contact exhaust pipes directly and maintain minimum 0.5" air gap for proper heat dissipation.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
15. 15

    Final inspection and test
    Reconnect negative battery terminal. Visually inspect entire exhaust system for proper alignment, clearances, and secure connections. Lower vehicle from jack stands. Start engine and check for exhaust leaks at all connection points (listen for hissing or ticking sounds). Allow engine to reach operating temperature and verify no unusual odors or smoke. Check for check engine light and scan for fault codes related to catalyst efficiency or oxygen sensor operation.
    ℹ️New catalytic converters may emit slight odor during initial heat cycles as manufacturing coatings burn off. This is normal and should dissipate after 20-30 minutes of operation.

Reassembly

1. Reinstall any belly pans or skid plates removed during preparation
2. Verify all tools and parts are removed from under vehicle before final lowering
3. Test drive vehicle for 15-20 minutes to fully heat exhaust system and verify no leaks or rattles develop
4. Re-check all clamp and bolt tightness after initial test drive as thermal cycling may require minor adjustments

Verification

• Start engine and listen carefully at all exhaust connections for any leak sounds during cold start and after reaching operating temperature
• Visually inspect exhaust system clearances with suspension at full droop and compression (have helper bounce vehicle)
• Use OBD-II scanner to verify no catalyst efficiency codes (P0420, P0430) or oxygen sensor codes appear after 50-100 miles of driving
• Verify exhaust system maintains minimum 10 inches ground clearance and does not contact chassis during normal driving conditions
• Check that oxygen sensor wiring is secure and not contacting hot exhaust components
• Confirm catalytic converter reaches proper operating temperature (glowing dull red in darkness is normal during sustained highway driving)

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