drexel_j Posted April 16, 2006 Share Posted April 16, 2006 I have a 92 LT1 with long tube headers and it won't go into closed loop mode and I think it's because the O2 sensors are at the end of the headers. If I install a 4 wire O2 sensor instead of the one wire does anyone know how I should wire them and what to use? Quote Link to comment Share on other sites More sharing options...
Bartman Posted April 16, 2006 Share Posted April 16, 2006 I previously had long tube headers installed on my LT1 with the oxygen sensors located at the end, so I'm not so sure that is your problem. Quote Link to comment Share on other sites More sharing options...
mark Posted April 17, 2006 Share Posted April 17, 2006 are you sure the ecu is seeing both 02 sensors? I have mine mounted way down stream on my 93 and it works fine. Quote Link to comment Share on other sites More sharing options...
drexel_j Posted April 18, 2006 Author Share Posted April 18, 2006 How would I see if the ECU is reading the O2 sensors; I have no trouble codes, it jsut won't go into closed loop mode and I understand that the system won't go into closed loop untill it reads the O2 sensors. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 18, 2006 Share Posted April 18, 2006 It wont go into closed loop mode until its up to a certain temp and ready a voltage signal from the oxygen sensor(s). Then it will start reading the O2 senors to adjust fuel/air ratios. It runs off pretuned maps before it goes into closed loop. So if your car is not going into closed loop its because your not reaching that specific temp and/or not getting a signal from your 02(s). There are other things that can cause it to stay in open loop. Certain codes will cause the PCM to go into open loop. This that might cause engine damage if it doesnt run "safe" in open loop. Do you have a check engine light or any codes present? Guy Quote Link to comment Share on other sites More sharing options...
drexel_j Posted April 19, 2006 Author Share Posted April 19, 2006 I don't have any codes; I do have a 160 thermostat but the engine does get up to 195 when the fan turns on, any more ideas? Quote Link to comment Share on other sites More sharing options...
80LS1T Posted April 22, 2006 Share Posted April 22, 2006 How do you know its not going into closed loop mode? It will pop out of closed loop if your 75%+ on the throttle also. Once you get off the throttle it will go back in but it takes a few seconds. Guy Quote Link to comment Share on other sites More sharing options...
drexel_j Posted April 23, 2006 Author Share Posted April 23, 2006 I am only checking it going into closed loop mode at idle; i am also having a problem with the idle dropping down to 500 600 RPM after a few minutes and then the car will die, it needs to maintain a 900 RPM idle. Quote Link to comment Share on other sites More sharing options...
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