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I’m confused on this one… I have lean codes on both banks and both banks are 0%stft and 25% ltft…. Raising the RPMs, does drive the trims lower, at 3000 rpm’s I’m around 10-12% right away I’m thinking vacuum leak…. Bank 1 o2 sensor up stream is normal operation, same as down stream bank 1…. This is where I get lost…. Bank 2, sensor is 800-850 mlv same as my downstream on bank two… the engine is adding fuel due to a lean condition on both banks but one bank has rich o2’s? why do I have rich o2’s on one bank? I can’t grasp this lol…. I added propane through the intake at idle to try and drive my trim numbers down, I was able to get them down to about 15% I also noticed my bank two o2 sensors (rich at all times) went lean but let’s say with some, minor hesitation also bounced up and down a bit. summary: codes for lean conditions on both banks, positive 25% ltft and bank two rich o2 sensors… What’s next?
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