Catalytic Converter for Hyundai Tucson (2017-2020) 2.0L 2.4L Rear

Direct-Fit Rear Catalytic Converter for 2017-2020 Hyundai Tucson (TL)

What it Does: This direct-fit rear underbody catalytic converter replaces the factory unit on the TL-chassis 2017-2020 Hyundai Tucson equipped with the Nu 2.0L G4NC or Theta II 2.4L G4KJ inline-four engine to restore compliant conversion of hydrocarbons, carbon monoxide, and nitrogen oxides.

The Stock Hyundai Tucson Catalytic Converter Failure

Over high mileage and repeated thermal cycling, the factory rear converter on the TL Tucson with the Nu 2.0L G4NC or Theta II 2.4L G4KJ engine suffers from precious-metal washcoat sintering and ceramic substrate fracture. Fuel trim imbalances, cold-start misfires, and road-salt corrosion accelerate cell melting and mat erosion inside the shell. Once the honeycomb brick breaks loose or clogs, exhaust backpressure spikes while downstream oxygen storage capacity drops below ECU thresholds, triggering persistent P0420 or P0430 catalyst efficiency faults.

Common Symptoms of a Failing OEM Catalytic Converter

• Check Engine Light / Efficiency DTCs: Stored P0420 or P0430 codes triggered when the post-catalyst oxygen sensor mirrors upstream switching waveforms.
• Metallic Underbody Rattle: Loose or fractured ceramic honeycomb chunks vibrating inside the converter housing during idle, deceleration, or road bumps.
• Excessive Backpressure & Failed Inspections: Sluggish throttle response under load, sulfur exhaust odor, and automatic failure of OBD-II emissions readiness testing.

The Direct-Fit Stainless Catalytic Converter Solution

Built to match factory underbody geometry (part #16646), this EPA-compliant replacement uses a corrosion-resistant stainless steel body (8-inch length, 5-inch height) and tubular piping to withstand thermal shock and underbody moisture. Inside, a high-flow ceramic honeycomb substrate coated with precious-metal washcoat restores HC, CO, and NOx conversion for OBD-II readiness without restricting exhaust scavenging. It retains the OEM 2-bolt inlet flange, welded hanger, slip-fit outlet, and single post-catalyst oxygen sensor port for a true bolt-on repair with zero cutting or welding.

What's Included

• 1 x Rear Underbody Catalytic Converter (Part #16646)
• 1 x 2-Bolt Flange Gasket
• 1 x U-Clamp
• 2 x Bolts with Nuts and Washers

Technical Specifications

Compatibility

• 2017-2020 Hyundai Tucson 2.0L I4: Fits SE, Value, SEL, and Limited trims (Rear Underbody Position).
• 2018-2020 Hyundai Tucson 2.4L I4: Fits 2018, 2019, and 2020 models only (Rear Underbody Position).
• Excluded Applications: Does NOT fit 2017 Hyundai Tucson 2.4L models or any Tucson equipped with the 1.6L Turbo engine.
• Emissions Restriction: EPA Federal compliant only; not CARB approved and not legal for vehicles registered in California, New York, Colorado, or Maine.

Frequently Asked Questions & Fitment Warnings

Does this fit the TL Tucson?

Yes. This is a direct fit for the 2017-2020 Hyundai Tucson equipped with the Nu 2.0L G4NC engine and 2018-2020 models with the Theta II 2.4L G4KJ engine. It does NOT fit the 2017 Tucson 2.4L, any 1.6L Turbo model, or vehicles registered in CARB-regulated states (CA, NY, CO, ME).

Will this clear P0420/P0430 codes, and are O2 sensors included?

Yes, if the fault stems from a depleted converter—oxygen sensors are not included. Installing a fresh ceramic substrate restores downstream oxygen storage to clear P0420/P0430 codes once upstream leaks, misfires, and fouled O2 sensors are resolved. Transfer your existing post-catalyst oxygen sensor or install a new OEM-spec sensor into the single factory port.

Are gaskets and mounting hardware included for installation?

Yes. The kit supplies the 2-bolt inlet flange gasket, outlet U-clamp, and two mounting bolts with nuts and washers. Allow the exhaust to cool completely, treat seized fasteners with penetrating oil, compare the unit against your original assembly before fitment, torque fasteners evenly, and inspect every joint for leaks at startup.

The Hyundai Precision Standard

Engineered for daily-driven reliability on the TL platform, this stainless rear converter maintains exact ECU backpressure targets and clean tailpipe chemistry over years of road-salt and heat-cycle exposure. Expect quiet underbody operation, leak-free flange sealing, and consistent OBD-II emissions compliance across all 46 federal-emissions states.