Pick the symptom that matches your car. See what a typical parts-first shop bills for it — versus what the root cause usually turns out to be once someone actually tests instead of guesses.
Choose the closest symptom.
Enter what a shop quoted you for this repair to see your own number. Leave it blank to use the typical figure.
Typical shop bill
$2,800
“Replace both catalytic converters”
What it actually was
$180
O2 sensor heater circuit fault — the cats test fine
Money left in your pocket
$2,620
94% of the quote was the wrong answer
The $180 part still needed fixing — an honest diagnosis doesn't make repairs free, it makes them correct.
Book a diagnosticThe scenarios above are representative misdiagnosis patterns we test for — common, well-documented failure modes in this industry — not customer testimonials. Your car's answer comes from testing your car. And if we can't find the root cause, you don't pay the diagnostic fee.