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Pontiac Transport 98 minivan

Roger Grandez's Avatar

Join Date: Aug 2004
Posts: 12

04-03-05, 03:05 PM   #1  
Pontiac Transport 98 minivan

Van has 65K miles, 6 cyl, and check engine light remains lit. OBD scanner shows code PO420, the catalyst system efficiency below threshold (cylinder bank no. 1). Can not find more details in repair books.
Also, the air bag light remains lit as well. Thank you, I would appreciate any suggestions or advice.

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billys68ss's Avatar

Join Date: May 2003
Posts: 1,459

04-03-05, 04:20 PM   #2  
For the airbag light you are going to have to get it scanned before we can tell you anything. There are a number of different things that can cause that light to come on.
The P0420 code simply means that the rear O2 Sensor is responding too quickly to the front O2 Sensors signal. This signal tells the PCM that the Catalytic converter is not converting the emissions like it is supposed to. You need to have it tested for proper operation. It will most likely be that the converter is bad. Were there any other codes? has there been other codes stored in the past?
Hope this is helpful to ya,

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