Replace the catalytic converter with a universal fit converter on a 2015 Kia Forte 1.8L I4, including removal of oxygen sensors and exhaust components.

Warnings

Tools required

Parts

• Universal catalytic converter × 1 — Size appropriately for 1.8L engine
• Exhaust flange gasket × 2 — Use OEM specification
• Exhaust adapter pipes × 1 — Match universal converter inlet/outlet diameter
• Exhaust clamps × 2 — 2.25 to 2.5 inch typical
• Exhaust hangers (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and allow exhaust system to cool completely (minimum 2 hours after last operation)
2. Raise vehicle on lift or securely support on jack stands at manufacturer lift points
3. Spray all exhaust flange bolts, oxygen sensor threads, and hanger bolts with penetrating oil and allow to soak for 15-20 minutes
4. Locate the catalytic converter positioned after the exhaust manifold and before the mid-pipe on the underside of the vehicle

Procedure

1. 1

   Remove heat shields
   Remove the exhaust heat shields covering the catalytic converter area using a 10mm socket. There are typically 2-3 heat shield sections secured with multiple bolts. Keep hardware organized for reinstallation.
   Torque spec

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

   Disconnect upstream oxygen sensor
   Locate the upstream oxygen sensor (before catalytic converter) and disconnect the electrical connector. Using a 22mm oxygen sensor socket, carefully remove the sensor by turning counterclockwise. Inspect sensor condition and threads. Set aside for reinstallation.
   ⚠Do not allow oxygen sensor to hang by its wire. Support the sensor to prevent wire damage.
   Torque spec

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

   Disconnect downstream oxygen sensor
   Locate the downstream oxygen sensor (after catalytic converter) and disconnect the electrical connector. Using a 22mm oxygen sensor socket, remove the sensor by turning counterclockwise. Keep sensors labeled to ensure correct reinstallation location.
   Torque spec

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

   Remove front flange bolts
   Support the catalytic converter with a jack or exhaust support stand. Remove the two bolts connecting the catalytic converter to the exhaust manifold flange using a 14mm socket. The flange may be stuck due to carbon buildup; tap gently with a hammer if needed. Remove and discard the old gasket.
   Torque spec

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

   Disconnect exhaust hangers
   Locate the rubber exhaust hangers supporting the catalytic converter and mid-pipe section. Using a pry bar or by hand, carefully unhook the exhaust pipes from the rubber hangers. Note the position for reassembly.
   Torque spec

   Hanger Bolts19 Nm (14 lb-ft)
6. 6

   Remove rear flange connection
   Remove the bolts connecting the catalytic converter outlet to the mid-pipe flange using a 14mm socket. Separate the joint and remove the old gasket. Lower the catalytic converter assembly from the vehicle.
   ⚠Catalytic converter may be heavy and awkward to handle. Use proper lifting technique and ensure adequate support.
   Torque spec

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

   Measure and cut exhaust pipes
   Measure the length of the removed OEM catalytic converter including inlet and outlet pipe sections. Mark cut locations on the existing exhaust system where the universal converter will be installed. Typical installation requires cutting before the front flange and after the rear flange. Use an exhaust pipe cutter or reciprocating saw to make clean, square cuts at the marked locations.
   ⚠Wear safety glasses and gloves when cutting exhaust pipes. Metal shavings and sharp edges present injury hazard.
8. 8

   Prepare universal converter and adapter pipes
   Test fit the universal catalytic converter between the cut exhaust sections. Measure and cut adapter pipes as needed to connect the universal converter inlet and outlet to the existing exhaust pipes. Ensure the converter is positioned to maintain adequate ground clearance (minimum 10 inches) and does not contact any vehicle components or heat shields.
   ℹ️Universal converter substrate direction matters. Flow arrow on converter body must point toward rear of vehicle.
9. 9

   Install oxygen sensor bungs
   If the universal converter does not have pre-welded oxygen sensor bungs, weld bungs at the appropriate locations to match OEM sensor positions (one before converter, one after converter). Ensure bungs are positioned to allow sensor wires to reach connectors without strain. Clean threads with wire brush.
   ⚠️Welding on vehicle requires disconnecting battery and protecting fuel lines, brake lines, and wiring from welding heat and sparks.
10. 10

    Install universal catalytic converter assembly
    Position the universal converter assembly with adapter pipes in place. Install exhaust clamps at both inlet and outlet connections but do not fully tighten yet. Ensure all pipes are properly aligned and the converter maintains correct orientation. Reconnect exhaust hangers to support the assembly.
    Torque spec

    Hanger Bolts19 Nm (14 lb-ft)
11. 11

    Install oxygen sensors
    Apply a thin coat of anti-seize compound to the oxygen sensor threads only, avoiding the sensor tip completely. Install the upstream oxygen sensor in the bung before the catalytic converter and tighten to specification. Install the downstream oxygen sensor in the bung after the catalytic converter and tighten to specification. Reconnect both electrical connectors.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
12. 12

    Final alignment and tightening
    Check entire exhaust system alignment ensuring no contact with frame, suspension, body, or fuel tank. Verify adequate clearance at all points (minimum 1 inch from heat-sensitive components). Tighten all exhaust clamps securely and evenly. Double-check that all oxygen sensor connectors are properly seated and secured.
    ℹ️Exhaust clamps should be tightened evenly to prevent leaks. Typical torque for band clamps is 40-50 ft-lbs.
13. 13

    Reinstall heat shields
    Reinstall all exhaust heat shields removed earlier. Ensure heat shields do not contact the exhaust pipes and maintain proper spacing. Install and torque heat shield bolts to specification.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Verify all exhaust connections are secure and properly aligned
2. Confirm oxygen sensor wires are routed away from hot exhaust components and have no tension on connectors
3. Check that all heat shields are properly installed and secured

Verification

• Start engine and listen for exhaust leaks at all connection points. A hissing sound indicates a leak requiring attention
• Allow engine to reach operating temperature and verify no unusual odors or smoke from exhaust system
• Use OBD-II scanner to verify oxygen sensors are reporting data and no catalytic converter efficiency codes are present (allow 50-100 miles of driving for readiness monitors to complete)
• Perform visual inspection under vehicle after test drive to check for any exhaust leaks, contact points, or loose components
• Verify adequate ground clearance and that exhaust system does not contact body or suspension during suspension travel

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