1997 Oldsmobile Aurora cold weather

1997 OLDSMOBILE AURORA
162,000 MILES • V8 • FWD • AUTOMATIC
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ERICARDOLARASALAZAR@YAHOO
  • MEMBER
  • 2 POSTS
when the weather starts to get cold i start getting code p0420 as well as a code for random multiple cylinder misfire, i have replaced the injectors, plugs,wires and ignition coils,o2 sensors. the car also has new fuel pump, alt batt air filter all done within the last 30000 miles all summer and fall i have no issues its been doing this for the past few years.
Nov 13, 2009 at 2:58 PM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
This is a tough one. A PO420 -- Catalyst System Efficiency Below Threshold (Bank 1). What I want you to try is this. Switch the O2 sensor from bank 1 to bank 2. Reset the computer and see if the problem follows the sensor. Also, have you checked for vacuum leaks? Have you checked the EGR to make sure it isn't carboned and not properly working? Has the catylatic converter been checked or replaced?

Let me know what you find.
Nov 13, 2009 at 10:51 PM
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ERICARDOLARASALAZAR@YAHOO
  • MEMBER
  • 2 POSTS
yes the converter has been replaced the p0420 code is on for all o2 sensors when i clear the light everything is fine for a couple weeks or so then it pops back on and this is all in the cold weather i will check the EGR valve
Nov 14, 2009 at 7:12 AM
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