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Old 03-21-2006, 06:15 AM
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Question runnig lean

my 99 z seams to be running lean in bank 1&2. Ive been told it is the mass airflow sensor by one guy and o2 sensors by another. anybody else got an idea on the problem
Old 03-21-2006, 12:25 PM
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Has your car ever been tuned? Mine was running rich at one point and a small tweak in my tune fixed it right away. I don't if the MAF would do that or not though???
Old 03-21-2006, 04:08 PM
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I'm not a hundred percent sure if it has been tuned or not i just bought the car about a month and a half ago but i'll look into that.thanks
Old 03-21-2006, 08:21 PM
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Are you throwing any codes? I talked to a friend, and he said it might be the MAF or 02 sensors, or it could be in the tuning. It could also be carbon buildup, which will def make it run lean.
Old 03-21-2006, 09:19 PM
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Question

yeah it was throwing two codes one that said bank 1 was running lean and bank 2 was running lean.how would i find out if it's carbon?
Old 03-22-2006, 12:06 PM
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i vote o2 sensors...somthing else if the car has headers it's gonna throw these codes untill you get the car tuned or install o2 sims
Old 03-22-2006, 06:47 PM
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thanks, the majority seems to be 02 sensors so i guess i will try that and get it tuned
Old 03-25-2006, 07:00 PM
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We swapped the O2's front to back (fronts were a little sluggish, but not dead) but that didn't cure it. Unplugged the MAF, and the LTrims went straight back to (near) 0 where they should be, from pegged @ 25% ... Swapped the MAF (ported stock) with a bone stock one I had sitting around, same deal - pegs 25% LTrim...

Sooo, still digging into this one




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