Check Engine Light Perth
$80 Diagnostic Scan
We Come To Your Driveway
Is your check engine light flashing, or is your car acting up unpredictably? Don't pay exorbitant dealership fees or sit in a workshop queue. Autova brings workshop-grade OBD2 computer scans and expert physical troubleshooting straight to your driveway across Southern River, Canning Vale, Gosnells, Piara Waters, Harrisdale, and Byford.
Full ECU scan, live sensor analysis, fault code clearing, and a written repair roadmap — all for $80 flat rate.
Exclusive neighbourhood special
Mention code DIAG80 when booking — Southern River locals only
What's Included
Our $80 Diagnostic Package,
Delivered to Your Driveway
Every item below is covered by the flat $80 fee. No hidden charges, no workshop markup.
P0420 — Catalyst System
Efficiency Below Threshold
P0420 is one of the most common check engine light codes in Perth. It means your ECU has detected that the catalytic converter is not converting exhaust gases efficiently enough. Before you spend $600–$1,800 on a new cat, get it properly diagnosed — the real cause is often a faulty oxygen sensor or an exhaust leak.
- Failing or worn-out catalytic converter
- Faulty downstream (post-cat) oxygen sensor
- Faulty upstream (pre-cat) oxygen sensor
- Exhaust leak before or after the catalytic converter
- Engine misfire that has overheated the cat
- Oil or coolant burning through a worn engine
A catalytic converter replacement costs $600–$1,800+depending on the vehicle. But P0420 is frequently caused by a faulty oxygen sensor ($120–$250) or an exhaust leak ($80–$200) — not the cat itself.
Autova performs a full live-data analysis — comparing upstream and downstream O2 sensor waveforms, checking for exhaust leaks, and reviewing fuel trim data — before recommending any repair. We won't quote you a new cat if a sensor is the real cause.
- 1Scan all modules and record every stored and pending DTC.
- 2Review live O2 sensor data — upstream sensor should switch rapidly; downstream should be relatively stable. If downstream is switching rapidly, the cat is failing.
- 3Check for exhaust leaks between the engine and the downstream O2 sensor — a leak can cause false P0420 readings.
- 4Review short-term and long-term fuel trims for signs of a lean/rich condition that could be damaging the cat.
- 5Inspect spark plugs and ignition coils for misfires that may have overheated the catalytic converter.
- 6Provide a written diagnosis with root cause confirmed before quoting any repair.
Why Choose Autova
Workshop-Grade Diagnostics,
Right on Your Driveway
Brands We Cover
Multi-Brand OBD2 Scanner Coverage
After Your Diagnostic
No Pressure. Just Clarity.
Once the scan is complete, we walk you through every fault code in plain English — no jargon, no scare tactics. You'll receive a full digital report emailed to you on the spot.
If repairs are needed, we provide an upfront fixed-price quote for parts and labour. You decide whether to proceed — same day, next week, or never. The $80 diagnostic fee is yours regardless.
If we do the repair, the $80 diagnostic fee is credited toward your total repair cost.
Stop guessing what's wrong with your car
Book online in under 2 minutes. We'll confirm your slot and dispatch a technician to your driveway — often the same day. Serving Southern River, Canning Vale, Gosnells, Piara Waters, Harrisdale, Byford, and surrounding Perth suburbs.
Southern River, Canning Vale, Gosnells, Piara Waters, Harrisdale & Byford. $80 diagnostic fee credited toward repair cost if you proceed with Autova.
Serving Southern River, Canning Vale, Gosnells, Piara Waters, Harrisdale, Byford & surrounds. View our full mobile mechanic service area →