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Discussion Starter #1
I have converted from OBDI to OBDII. For some reason my car did not come with heated O2 sensors, but pretty much every other car did. My question is, could this mess with being able to control my A/F's?

I am running a MAP-ECU V2 with and O2 simulator, and a Zeitronix WB that has an analog output, and then a single stock O2 sensor in the downpipe. I have tried plugging these into the 3 oxygen signals into the ECU, but it doesn't do anything.

At idle I can't get it to run anything but 12.7, no matter how much I lean out the mixture. I need to get this to pass emissions and a 12.7 just won't cut it.

I need to know if the OBDII ECU also needs to know if the O2 sensor is even there by sensing the heating element.

And then there is the EGR temp sensor. On most vehicles I have worked on, this will cause a loss in gas mileage and cause the engine light to go on. Is that the case for this?
 

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Why did you go from OBDI to OBDII .. they say its alot harder to tune .. but about hooking up your O2 sensor question, MAP ECU's FORUM would be your best bet to find the information you are looking for. Just make a screen name and post your question in the correct section and they will answer your questions to the best of their knowledge.

Mike
 

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Discussion Starter #3
because I am NA-T. NA OBDI are Karmen Vortex. It is noted that KV does not take kindly to large changes, and since I am running 780cc injectors, I decided to go OBDII to go MAF instead.

FYI, I didn't post in the NA section because this is an question that is applicable to all OBDII 2JZ's.

I will check out the MAPECU forums, but with that link I found, that pretty much answered my question. Not having the heater/s hooked up WILL CAUSE A RICH IDLE.
 

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you are not clear, what do you mean your car didn't come with a heated 02 sensor. I am not sure if you read how to do the mod correctly, but when converting to OBDII one of the side effects are that the primary 02 sensor is no longer heated until you swap a pin around on the harness.

I have converted from OBDI to OBDII. For some reason my car did not come with heated O2 sensors, but pretty much every other car did. My question is, could this mess with being able to control my A/F's?

I am running a MAP-ECU V2 with and O2 simulator, and a Zeitronix WB that has an analog output, and then a single stock O2 sensor in the downpipe. I have tried plugging these into the 3 oxygen signals into the ECU, but it doesn't do anything.

At idle I can't get it to run anything but 12.7, no matter how much I lean out the mixture. I need to get this to pass emissions and a 12.7 just won't cut it.

I need to know if the OBDII ECU also needs to know if the O2 sensor is even there by sensing the heating element.

And then there is the EGR temp sensor. On most vehicles I have worked on, this will cause a loss in gas mileage and cause the engine light to go on. Is that the case for this?
 

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Discussion Starter #6
my 1994 lexus GS300 stock ECU did not use heated O2's at all. There are no wires there.

I have added all the neccesary wires to the ECU.

Altogether I added:

post cat O2 sensor signal wire
post cat O2 sensor heater wire
primary O2 sensor heater wire
secondary 02 sensor heater wire
diagnostic wire
EGR temp sensor

I still need a crank sensor wire, but I don't have a crank sensor.

I have added resistors to all the heater wires so the ECU thinks they are there, and all three receive an O2 signal, but I run rich.

The only thing I can think of now is that the ECU needs the crank signal in order to run properly.
 
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