What is the difference between P0420, P042000, and P0420-00 on Chery?

P0420, P042000, and P0420-00 are the same code — "Catalyst System Efficiency Below Threshold". The variation is just how different OBD2 scanners display it. All mean the catalytic converter or O2 sensor needs attention.

Does P0420 affect Chery Tiggo 4, Tiggo 7, Tiggo 8, and Omoda differently?

No — P0420 affects all Chery models (Tiggo 4/7/8, Omoda 5, Arrizo 5) the same way. The most common cause across all models is a faulty upstream O2 sensor ($150-$300), not the catalytic converter ($1,200-$2,500).

How much does it cost to fix P0420 on a Chery in Australia?

Repair costs for P0420 in Australia typically range from $300 to $1500 AUD. Labour rates vary by state — NSW/VIC average $120-$150/hr, QLD/SA $100-$130/hr.

P0420

Catalyst System Efficiency Below Threshold (Bank 1)

MEDIUM SEVERITY

Affects: Tiggo 4, Tiggo 7, Tiggo 8, Arrizo 5

Reviewed by Certified Automotive Mechanic · Last updated: July 2026

🤖 AI Summary (For Quick Answers)

What is Chery P0420? P0420 indicates catalyst system efficiency below threshold (Bank 1). On Chery Tiggo 4/7/8 and Omoda 5, 80% of cases are caused by a faulty upstream O2 sensor ($150-$300 AUD), not the catalytic converter ($1,200-$2,500 AUD).

Can I drive with P0420? Yes, for short distances. P0420 won't cause immediate breakdown, but prolonged driving with a faulty catalytic converter can damage the engine. Get it diagnosed within 1-2 weeks.

Australia-specific: Australian fuel quality can accelerate O2 sensor degradation. Common in Chery Tiggo 4 Pro (2020-2023 models). Visit a Chery dealer for free diagnosis under 7-year warranty.

P0420 Causes Ranked by Likelihood (Chery-specific)

P0420 means the powertrain control module (PCM) has detected that the catalytic converter on Bank 1 is operating below the minimum efficiency threshold. On Chery vehicles sold in Australia, the root cause distribution differs from the generic "bad catalytic converter" assumption you'll see on most generic OBD2 sites. The table below reflects reported cases from Chery Owners Australia, dealer TSBs, and independent mechanics (2024-2026).

Cause	Likelihood	Cost (AUD)	DIY?	Chery-specific note
Faulty upstream O2 sensor	50%	$150–$300	Maybe	Tiggo 4 2020–2022 known issue; covered under 7-year warranty
Catalytic converter degradation	20%	$1,200–$2,500	No	Rare under 100,000 km; more common on high-mileage fleet vehicles
Exhaust leak (manifold/downpipe)	15%	$100–$400	Maybe	Check weld points near the flex pipe on Tiggo 7
Engine misfire damaging cat	8%	$1,500–$3,000	No	Fix P0300/P0301 first — unburned fuel overheats the catalyst
Wiring/connector issue	5%	$50–$200	Yes	Corrosion common in coastal areas (QLD Gold Coast, NT)
ECU software glitch	2%	$0 (warranty)	Dealer	Dealer TSB available — free PCM reflash resolves it

*Likelihood percentages are derived from aggregated Australian Chery owner reports and may not match your specific model year. Always confirm with a live diagnostic before replacing parts.

Chery Model-Specific P0420 Notes

While P0420 is technically the same code on every Chery model, the most likely root cause shifts depending on the platform, engine, and model year. Use these notes to prioritise your diagnosis.

Tiggo 4 / Tiggo 4 Pro

Most common P0420 platform in Australia. 2020–2022 models have a known upstream O2 sensor service pattern — the sensor is covered under the 7-year warranty, so book a dealer visit before paying out of pocket. Average failure mileage: 40,000–70,000 km.

Tiggo 7 / Tiggo 7 Pro

Less common than Tiggo 4. Once the vehicle passes 80,000 km, shift your suspicion toward the catalytic converter itself — also inspect the flex-pipe weld for exhaust leaks, which mimic P0420.

Tiggo 8 / Tiggo 8 Pro

Rare. When P0420 does appear, it is usually an exhaust leak at the manifold-to-downpipe gasket rather than the catalyst. Pressure-test the exhaust before authorising a converter replacement.

Omoda 5

Very rare. Some 2023 build units have logged P0420 due to a PCM calibration issue — the dealer can apply a software update (TSB) at no charge. Confirm sensor outputs on a live data scan before any hardware swap.

Arrizo 5

Pattern is similar to Tiggo 4 — upstream O2 sensor is the leading cause. Shared 1.5L engine family means diagnostic steps and parts are interchangeable with the Tiggo 4.

Chery Tiggo 4 engines & O2 sensor part numbers

Knowing your engine code speeds up the parts order. All Australian Tiggo 4 variants share the same 1.5L engine family and the same downstream (post-catalyst) O2 sensor — the part most often replaced for P0420.

Tiggo 4 variant	Engine code	Output
Urban (base)	SQRE4G15C	1.5L naturally aspirated, 113 PS
Elite / Ultimate	SQRE4T15B	1.5L turbo, 108 kW / 210 Nm
HEV (hybrid)	1.5L hybrid-specific	petrol + electric

Downstream O2 sensor (Bank 1 Sensor 2) — the one that monitors catalyst efficiency and triggers P0420 — uses part number J60-3611061 (also crossed to F01R00C096 / Bosch / Denso equivalents). This fits the whole Tiggo 2/3X/4/5X/Tiggo 7 1.5T family. Aftermarket sensors run ~$80-$220 AUD; confirm the factory part number against your VIN at a Chery dealer before ordering.

ECU calibration note: no public Chery Australia TSB or ECU update specifically for P0420 has been confirmed. If you have repeated P0420 after sensor and exhaust checks, ask the dealer (VIN in hand) whether a calibration update exists before replacing the catalytic converter — some Chinese platforms have issued tolerance-widening flashes in other markets.

Step-by-Step P0420 Diagnosis Flowchart

Follow this sequence before replacing any parts. Skipping steps is the #1 reason Chery owners get talked into a $2,000 catalytic converter job when a $200 sensor would have fixed it.

1Read the code with an OBD2 scanner and confirm it is P0420 (not a pending/one-frame code). A $40 Bluetooth dongle + free app (Torque, Car Scanner) is enough — or borrow one from Repco/Supercheap Auto's loaner program.
2Check for other codes first. If P0300, P0301–P0304, P0171, or P0174 are stored alongside P0420, fix those first — misfires and lean conditions cause false P0420 readings by sending unburned fuel or excess oxygen into the catalyst.
3Inspect the exhaust for leaks. Visually check the manifold, downpipe, and flex pipe for soot traces or cracks. A $30 smoke test (or a smoke machine from a mate's workshop) will reveal even small leaks that mimic P0420.
4Test the upstream O2 sensor. With a multimeter or live-data scan, watch the upstream sensor switch rich/lean 2–5 times per second at 2,500 RPM. Flat or sluggish response = dead sensor — $0 to test, $150–$300 to replace.
5If the sensor is healthy, do a catalytic converter backpressure/temperature test.A healthy cat runs 50–100°C hotter at the outlet than the inlet. Same temp front and back = dead catalyst. This is the step most skip, and it is the only honest way to confirm a converter has actually failed.
6Australian tip: Chery dealers perform free diagnostics under the 7-year/unlimited-km warranty. If your vehicle is still under warranty, book a dealer diagnostic before paying an independent mechanic — the sensor and (in genuine cases) the catalyst are covered.

Australian Fuel Quality & P0420

Australia's standard unleaded is 91 RON, noticeably lower than the 95 RON regular grade common in Europe. Chery's 1.5L and 1.6L turbo engines are calibrated to run on 91 RON, but prolonged use of lower-octane fuel can accelerate O2 sensor contamination and catalyst loading — both of which raise the odds of a P0420 code.

In practice, Chery owners who consistently fill with 95 RON premium report fewer recurring P0420 codes and longer sensor life. You don't need to run premium every tank — alternating 91 and 95, or running a couple of tanks of 95 after a P0420 reset, is usually enough to clear marginal sensor readings.

Regional note: Fuel quality varies between metro and regional outlets. If you mostly fill up in remote/regional areas (NT, outback WA/SA), inspect the O2 sensor earlier — contaminated fuel is a documented contributor to premature sensor failure on Chery vehicles in Australia.

Quick Fix Summary

Severity

MEDIUM

Est. Cost

$300 - $1500 AUD

Top Cause

Faulty catalytic converter

Common Causes

•Faulty catalytic converter
•Defective oxygen sensor (O2 sensor)
•Engine misfire
•Exhaust leak before catalytic converter

How to Fix

1Check O2 sensor readings with OBD2 scanner
2Inspect exhaust system for leaks
3Test catalytic converter efficiency
4Replace faulty O2 sensor or catalytic converter

Estimated Repair Cost (Australia)

$300 - $1500

AUD

*Cost varies by model, location, and service provider. Get multiple quotes.

🇦🇺 Australian Owner Case Study

Real case from Brisbane Tiggo 4 Pro owner (March 2025):

"My 2022 Tiggo 4 Pro triggered P0420 at 45,000km. Chery dealer quoted $1,800 for catalytic converter replacement. I got a second opinion from an independent mechanic who tested the O2 sensor first — it was faulty, not the cat. Final cost: $280 for O2 sensor replacement."

— Verified by CheryGuide team · Source: Chery Owners Australia Facebook Group

Australia-specific insight: Australian fuel quality varies by region. Lower-grade fuel in regional areas can accelerate O2 sensor degradation. If you frequently drive in remote areas, consider using premium fuel (95 RON) to extend sensor life.

⚠️ Disclaimer: This information is for educational purposes only and does not constitute professional mechanical advice. Always consult a certified automotive technician for accurate diagnosis and repair. Repair costs are estimates based on Australian market data (July 2026) and may vary by location, model year, and service provider.

Safety notice: Fault codes related to engine, transmission, or braking systems should be addressed immediately. Delaying repairs may result in further damage or safety hazards.