Smog Check Guide
Yes 1998 model year and newer. Under 14000 lbs gvwr. Biennial inspection required. Heavy-duty falls under clean truck check.
Source: California Bureau of Automotive Repair (BAR) smog check program.
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Yes 1998 model year and newer. Under 14000 lbs gvwr. Biennial inspection required. Heavy-duty falls under clean truck check.
No tailpipe sniffer. OBD scan only. Visual emissions component inspection. Smoke opacity test for some.
1998 and newer diesel vehicles at or under 14,000 lbs GVWR require California smog inspection using OBD-II scan plus a visual check of all emissions control equipment. Diesel Particulate Filter (DPF) must be present and unmodified — removal is an automatic fail on visual inspection and OBD. Exhaust Gas Recirculation (EGR) system must be intact; deleted EGR triggers fault codes and visible fail. Diesel Exhaust Fluid (DEF) system on 2010+ diesel vehicles must be functional; limp-mode from DEF faults equals automatic fail.
Specialized OBD equipment. Visual smoke inspection. DPF and emissions component checks. Longer inspection time.
Diesel Particulate Filter — yes, it must be intact and functional. DPF removal causes immediate smog fail. Visible tampering rejection. OBD-II catches DPF deletes.
Yes if it triggers the OBD system into 'not ready' or active fault state. DEF dosing issue is visible in OBD logs. Limp mode = smog fail. Needs repair before retest.
Yes visual inspection catches it. DPF removal is illegal in California. Must restore stock DPF to pass. BAR can impose fines.