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Discussion Starter · #1 ·
I have a USDM K20A2 setup in a 93 EG all stock. Attached is the parametersin .pdf format. I changed the extension to .doc so that I can attach it to this thread. Once downloaded please change extension to .pdf.

I have my parameters setup in K-Manager and have a few questions that you guys can help me with.

1. Under the VTEC Options, does the VTEC oil pressure switch enabled box be checked? I read under the help options that with the JDM K20A type-r motor this option should be disabled.

2. Closed Loop, Is it ok to run close loop regardless of climate change? If you look at the the datalog sheet 14 my AF is 28.76:1 at 899 rpm idle. When I switch to closed loop it jumps to 38:1. Is this normal AF mixture or is there something wrong with my primary O2 sensor? Where should the AF be at closed or open loop? What would you recommend open or closed loop for a daily driven car.

3. Idle, Where should my idle speed be set at? Is it ok at 900 RPM? Where should the idle valve duty cycle adjustment be at?

My main concern is the primary O2 sensor. I don't know if 28:1 AF is correct? What are normal AF at idle?

Any answers or recommendations are welcomed.
 

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1. vtec pressure is just that, the jdm motors dont bring a pressure switch so obviously if its turned on the computer will look for it and give you a DTC code for it, so if you have a usdm motor enable it because u have it and its nice to know that u have oil pressure. if you had a jdm motor you would disable it to avoid a code.

2. open loop is for when your not tuning and just want to let your ecu do the calcuations for you and decide what changes should be made because of the weather and such. closed loop basically just lets you tune without having the computer make changes on top of your tuning otherwise your settings will be off.

3. stock idle is 750 and duty would be in the middle. depends where you want your idle to be at, with stiffer mounts for hybrids the chassis can definitely vibrate so setting it higher until u find a nice soft spot is nice. the duty cycle ive never really understood but it behaves with the idle so if inputting in an idle of 900 doesnt change anything moving the duty up a lil helps same with lowering it. i think this takes a lot of playing around with because when the rpms drop your idle might go down too low as well..

4. your A/F ratio sounds like its off bigtime if you look at the lamda chart you will see that everything under low and mid throttle/load is supp to be around 14.7 a/f and heavy load at WOT is 13.2, so your idle needs to be around 14.5-7 and anything in the 16s is very lean so your reading of 20+ doesnt seem right i dont know what is giving you that reading but try another calibration. i had one that gave me some dumb high readings, but yet another would work perfect and others would give me o2 cel codes from hell and it the o2 wouldnt even work.
 

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Discussion Starter · #3 ·
Thanks for the input, but I thought that open loop is for tuning and closed loop is for when you let the ECU control the AF.

Do you think my primary O2 sensor is bad? Even with other calibrations the AF reads 28:1 - 30:1. I bought a new primary O2 sensor but don't want to put it in yet until I know the O2 is bad.
 

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re-read my open loop answer, i think you just said what i explained already.
and no way your a/f readings are supposed to be that high. something is def wrong if the car sounds normal. def stick that other o2 in there and see what it reads.
 

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Discussion Starter · #5 ·
2. Closed Loop, Is it ok to run close loop regardless of climate change? If you look at the the datalog sheet 14 my AF is 28.76:1 at 899 rpm idle. When I switch to closed loop it jumps to 38:1. Is this normal AF mixture or is there something wrong with my primary O2 sensor? Where should the AF be at closed or open loop? What would you recommend open or closed loop for a daily driven car.

I bought a new O2 sensor and put it in yesterday. I ran datalog under K-Manager and the AF reading is +- 28:1. When I go part or full throttle it doesn't go any lower than 25:1, but if I let off the gas pedal and decelerate then the AF goes to 15, 16, 17:1 then goes back up to 28:1. I'm thinking that maybe the O2 harness is wired incorrectly. Please help if anyone is having the same kind of problem.
 
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