Failed Smog Check Repair in Pasadena, CA

Failing a smog check is stressful, especially when someone tells you that you need a new catalytic converter. Often you don't. One of our customers had a '99 Nissan Frontier that failed and he was sure the converter was shot. Arthur ran a diagnostic and found it only needed an O2 sensor. Another customer's 1996 Camry had been a struggle elsewhere, and she wrote that Arthur "worked so hard to get my car to pass." That's the approach on every failed smog we see.

Common reasons cars fail smog

• Check engine light on: an automatic fail, regardless of how the car runs.
• Readiness monitors not set: common after a battery change or cleared codes.
• Oxygen sensors: aging sensors respond slowly and throw off the fuel mixture.
• Vacuum leaks: cracked or disconnected hoses, sometimes a two-minute fix.
• Misfires: worn plugs, coils or wires raise hydrocarbons. See engine tune-up.
• High NOx: often an EGR problem or an engine running too lean or too hot.
• Catalytic converter: sometimes it really is worn out, but usually something else killed it.
• Visual or functional failures: missing or modified emissions parts, a bad gas cap, an EVAP leak.

Diagnose first, then repair

We read your failure report, scan the computer, check live data, and test the suspect component before calling it bad. If the converter failed, we find out why, a misfire or oil burning will kill a new one too. Then we give you a clear quote and do the repair. Rennsen's Nissan Rogue was a good example: the parts store said O2 sensor, Arthur found a disconnected hose, then had him drive to reset the emissions computer before the retest. It passed.

Retest here

Once the repair is done and the monitors are ready, we retest at our STAR Certified smog station. Our sign also lists CAP; ask us whether the state's Consumer Assistance Program could help with your repair costs. More in our post on what to do after a failed smog check.