An oil change could help pass the smog check, specially if the oil is old and saturated with fuel (Hydrocarbon - HC). High HC in the intake will cause your Kia to run rich and produce high CO; both of which will cause it to fail the smog test. So if it's been a while since the last oil change, we recommend getting it replaced before the smog test. As far as the tailpipe, depending on how dislodged the tailpipe is, you may or may not need to get it welded first. If the exhaust pipe is seeping oxygen into the exhaust in high amounts and because of a break somewhere allow the exhaust system after the catalytic converter, the smog machine may not be able to initiate the smog inspection due to what is referred to as "dilution". Dilution occurs when high amounts of oxygen enter the smog machine's testing board, rendering the smog test inaccurate. When the smog check machine senses dilution it will not allow the smog technician to continue the inspection or in cases with very high dilution exists, the machine may not even let the technician begin the smog check. You should check with a smog station before they begin inspecting your Kia so that you don't end up having to pay for a failed smog test.
posted by SmogTips Support
