black00chev Posted December 24, 2009 Author Report Share Posted December 24, 2009 Ok that was the main part I wasnt sure about. Guess ill be searching for two O2s here very soon. Anyone with an idea where I should pick those up and what brand? Quote Link to comment Share on other sites More sharing options...
SSplaytoy Posted December 24, 2009 Report Share Posted December 24, 2009 Bosch are nice and what I went with, but they are pricey. Shop around online to find the best deal. You can find them at the local autopart store, but it will still cost some $$$$ Quote Link to comment Share on other sites More sharing options...
misterp Posted December 24, 2009 Report Share Posted December 24, 2009 8 UR HMI found a eBay seller who had them for $65 each (about 1/3rd off retail). Mr. P. Quote Link to comment Share on other sites More sharing options...
black00chev Posted December 24, 2009 Author Report Share Posted December 24, 2009 Ill have to check em out... As far as the STFTs go, I kept an eye while cruising around and heading back home after some last minute stops in town. While crusing they did NOT stay within +-2%. While sitting at a light they would eventually zero out and maybe fluctuate a little but not much. While getting into the throttle fairly hard (not wot) they will zero out for a couple seconds and then start fluctuating again. Quote Link to comment Share on other sites More sharing options...
black00chev Posted December 27, 2009 Author Report Share Posted December 27, 2009 Bump for STFT readings in previous post! Quote Link to comment Share on other sites More sharing options...
Krambo Posted December 27, 2009 Report Share Posted December 27, 2009 (edited) While crusing they did NOT stay within +-2%. While sitting at a light they would eventually zero out and maybe fluctuate a little but not much. They will bounce around at different RPM's / cylinder airmass unless you have done meticulous Ve and MAF tuning and your fuel (STOICH) is consistent. Regardless, the STFT's job is to correct cruising fuel issues so some fluctuation is normal. What are your LTFTs? In your case, they will most likely tell you more about your issue as it seems chronic and more than likely have influenced your LTFTs by now. Anyway, replace those old sensors prior to chasing a perceived problem...pondering fueling issues with old faulty sensors is a waste of time. While getting into the throttle fairly hard (not wot) they will zero out for a couple seconds and then start fluctuating again. More than likely, you went into Pe mode at this point for a brief moment. The throttle % it takes for Pe mode to occur can be changed in the tune file to whatever you wish...it isn't necessarily (and shouldn't be) set at full 100% throttle. Edited December 27, 2009 by Krambo (see edit history) Quote Link to comment Share on other sites More sharing options...
misterp Posted December 27, 2009 Report Share Posted December 27, 2009 (edited) Ill have to check em out... As far as the STFTs go, I kept an eye while cruising around and heading back home after some last minute stops in town. While crusing they did NOT stay within +-2%. While sitting at a light they would eventually zero out and maybe fluctuate a little but not much. While getting into the throttle fairly hard (not wot) they will zero out for a couple seconds and then start fluctuating again. How STFT and LTFT work - as you drive and the PCM decides that the fueling is off, it will increment or decrement the STFT values; if the amount of correction via STFT is needed all the time, the PCM will increment/decrement LTFT for that bank. Total fueling adjustment will be LTFT + STFT, so as an example if you have a LTFT of 5% and a STFT of 3% then a sensor or your tune (or both) is off 8%. Another thing to remember is that even new O2 sensors are totally guessing when the actual AFR is within +-3% of perfect, they're just not labratory grade instruments. Mr. P. Edited December 27, 2009 by Mr. P. (see edit history) Quote Link to comment Share on other sites More sharing options...
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