Your Vehicle Failed Its Smog Test. We Fix the Problem and Get You Passing Fast.

Signs Your Vehicle Has an Emissions Problem

  • Check engine light was on when you went in for testing

  • Visible smoke from the exhaust when starting or driving

  • Strong fuel or exhaust smell inside or outside the vehicle

  • Vehicle runs rough, hesitates, or misfires under acceleration

  • Fuel economy has dropped noticeably in recent months

  • You received a smog failure certificate listing specific fault codes

Failed Emission Testing Repair Services in Atascadero

A smog failure puts your vehicle registration on hold and your schedule in limbo. We diagnose the specific cause of your failure, make the targeted repairs, and get your vehicle ready to pass before you return to the smog station. No unnecessary work, no wasted trips.

Oxygen Sensor Replacement

Faulty oxygen sensors are one of the most common reasons vehicles fail emissions testing. We test and replace O2 sensors to restore proper air-fuel mixture control and bring your exhaust readings back into compliance.

EVAP System Repair

We locate and repair leaks from a faulty gas cap to a failed purge valve to resolve this common failure point.


Catalytic Converter Service

A failing catalytic converter raises hydrocarbon and carbon monoxide readings and routinely triggers smog failures. We inspect your converter and replace it with a quality unit that meets California emissions standards.

Ignition System Service

Worn spark plugs or failing ignition coils cause misfires that send unburned fuel into the exhaust and spike hydrocarbon emissions. We service your ignition system to eliminate misfires and restore clean combustion.

EGR System Service


A stuck or clogged EGR valve causes elevated NOx emissions and smog failures. We clean, repair, or replace EGR components to bring your nitrogen oxide readings back within the state-required limits.

Post-Repair Emissions Rete

After completing your repairs, we perform an in-house emissions check to confirm your vehicle is ready to pass before you return for your official smog test.

Why Choose APS for Your Failed Emission Testing Repairs?

Experienced Technicians

Our mechanics specialize failed emissions test repair, bringing expertise that other shops simply can't match.

Honest Diagnostics

We tell you exactly what's wrong and what it takes to fix it, nothing more, nothing less. No upselling, no surprise charges.

Clear Communication

No confusing jargon, just straightforward explanations of what your vehicle needs.

Fair, Transparent Pricing

You'll receive a detailed estimate before we begin any work. We respect your budget and your time.

Fast Turnaround

We know you need your vehicle. Our efficient workflow gets you back behind the wheel as quickly as possible without cutting corners.