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Old 11-09-2012, 07:11 AM
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joyism5 joyism5 is offline
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Location: USA
Join Date: Jan 2011
Posts: 1,271
Mein Auto: '99 740IL, K75RT
I know nothing about the inpa code but the thermostat error and missfires + the lamba code make a little sense to me. I think that the heating element inside the thermostat went bad and the engine can't keep up with the setting for the temperature, which is controlled by DME. This thermostat should open at 103 C degrees (100 is the boiling point for water), and I think that if does not open when supposed to, all the air-fuel ratio is messed up. This would be my explanation for the misfire. There ways that you can test the thermostat. I remember a talk about that long time ago.
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