jonlabree Posted February 19, 2012 Share Posted February 19, 2012 Anyone know how to hook up a heated O2 sensor? Link to comment Share on other sites More sharing options...
2seater Posted February 19, 2012 Share Posted February 19, 2012 Three wire? The couple I have fooled with use a standard single wire for the sensor and two heavier wires for the heater, one is grounded and the last one is supplied with 12v from an ignition source. The ones I worked with were not polarity sensitive. Other than that, I cannot help. Link to comment Share on other sites More sharing options...
padgett Posted February 20, 2012 Share Posted February 20, 2012 My understanding is that the sensor is the same as a one-wire. The heater is to allow a faster light off and to get any advantage you would need to shorten the delay for closed loop and make sure the heater is only on for a few seconds at startup.That said there are also wide range sensors but that would require remapping. Link to comment Share on other sites More sharing options...
2seater Posted February 21, 2012 Share Posted February 21, 2012 I looked into this a bit further and the heater in the sensor is to be be powered whenever the engine is running. MegaSqurt uses the fuel pump relay to power O2 sensor heater, although I would use an independant relay triggered by an ignition source. It looks like the difference between a three and four wire is case ground for the three wire sensor or independant ground for the four wire. The heater uses two wires in either case.I have a couple of new heated sensors and will check the amp draw as soon as I get the chance. Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted February 21, 2012 Share Posted February 21, 2012 2seater, what do you think using a heated O2 sensor will do for you if the ECM still won't enter closed loop operation until the engine reaches its set point temperature by which time a non-heated sensor will be inside its operating temperature as well? Link to comment Share on other sites More sharing options...
2seater Posted February 21, 2012 Share Posted February 21, 2012 I am certainly no expert on this subject. I have seen comments elsewhere that it speeds up the closed loop operation, but I do not see how that would be possible without reprogramming? There appears to be a couple of possible advantages, one I have observed, and the other is anectdotal from other websites. First, on occasion, I have observed my O2 sensor would become inactive after extended idle periods, ostesibly from becoming too cool. I believe the heater would improve this situation. The second is conjecture that the sensor lasts longer when subjected to alternate fuel blends, such as race fuels (leaded?). I don't know if this may retard harmful deposit buildup or how it may help. Link to comment Share on other sites More sharing options...
padgett Posted February 22, 2012 Share Posted February 22, 2012 Thought I said that: "need to shorten the delay for closed loop" - that requires reprogramming (but I know which byte). Do not understand why it would need heat while engine is running. Link to comment Share on other sites More sharing options...
2seater Posted February 22, 2012 Share Posted February 22, 2012 I agree with you Padgett, just sort of rolled everything into one reply. I don't know why it would require continuous heat either, but the diagrams I found appeared to have constant power applied? Link to comment Share on other sites More sharing options...
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