A check engine light can mean a $15 gas cap or a $2,000 catalytic converter — the difference is proper diagnosis. For Mountlake Terrace drivers on the I-5 corridor and 236th commute routes, Tom's B&M Auto uses factory-level bi-directional scan tools that read live data streams, not just stored codes. We find the actual cause, not just the symptom. Diagnosis fee credited toward repair if you proceed with us.
We connect a factory-level bi-directional scan tool and pull stored fault codes, pending codes, freeze frame data, and live sensor readings. Many root causes only appear in live data — not stored codes.
We interpret the codes in context of your vehicle's specific make, model, and engine. A P0420 code on a Subaru has different common causes than on a Toyota. We diagnose to the component level before quoting.
Written repair estimate before any work begins. Diagnosis fee credited toward repair. Post-repair re-scan to confirm all codes are resolved and monitors are set.
A flashing check engine light means an active misfire that's damaging your catalytic converter in real time — that's a same-day repair. A steady light is less urgent but shouldn't be ignored; some fault codes trigger secondary codes when left unaddressed, turning a $200 oxygen sensor into a $1,500 converter replacement.
We don't clear codes and hope they don't come back. We find the root cause and fix it. Common causes we diagnose regularly: oxygen sensors, catalytic converter efficiency (P0420/P0430), evaporative emission leaks, ignition coil misfires, MAF sensor contamination, and EGR valve carbon buildup on high-mileage engines.
Live data streams, not just stored codes. Root cause diagnosis.
Diagnosis cost applied toward repair if you proceed with us.
Domestic, Japanese, European. Manufacturer-specific fault code coverage.
Check engine light diagnosis includes a factory-level OBD-II scan reading stored codes, pending codes, and live sensor data; root cause identification to the component level; and a written repair estimate before any work begins. Diagnosis fee credited toward repair.
From Tom's B&M Auto - serving Mountlake Terrace and the greater Seattle metro.
Tom's B&M Auto · 17820 Hwy 99, Suite E, Lynnwood · Serving greater Seattle
Also serving: Edmonds, Mountlake Terrace, Shoreline, Mukilteo, Kenmore, Alderwood Manor