QuestionI have a 2000 jetta with 65000 miles. The check engine light is on and the code is P1424 which says Secondary Air Injection System Bank 1 Leak Detected. I went to a local garage and he found nothing leaking and he said there was something wrong with the oxygen sensor. Is this possible? Because the code says there is something leaking. Could you tell me how I can fix this problem? Does this a matter? Thanks.
AnswerHello Huan;
Don't go back there. The oxygen sensor has nothing to do with the secondary air system. Oxygen sensors are used to determine how much unburned fuel has gotten into the exhaust stream. They tell the computer how much fuel should be introduced to the cylinders on the upcoming series of firings of the spark plugs, and the "power" stroke of the 4 cycle engine.
So, now to the specific issue. I am left to presume that your car is a 4 cylinder, 2.0 litre, with an engine code of "AEG." The secondary air system consists of a pump that is electrically powered, and controlled by the computer to turn on, and help the catalytic converters work to burn the unburned fuel that come out of the exhaust port into the exhaust system, so before it escapes in to the atmosphere, cold air is pumped into the exhaust, and this helps the rest of the fuel burn, so it doesn't pollute. The pipes that carry this pumped air are mostly plastic, and they crack, and lose air without getting it where the computer wants it to go, so the code comes form that. I would suggest inspecting all of the piping, and also inspecting all of the vacuum hoses that tell the computer what the driving conditions are. It's also possible that the pump itself is dead, and not running, or that the pump, since it has two moulded plastic halves that are riveted together may be beginning to split, and not holding, or making enough pressure. So, just check all of that stuff. I hope this helps. Good luck, Huan.
