o2 control gurus please chime in! Haltech Elite 1500 O2 control for ITB setup , alpha N, VE tuning with Map compensation overlay

Hi guys,

I've finally decided to go with VE tuning method for my ITB Honda. Always been running pulsewidth tuning the old school way, Alpha N, tuning all the load sites very closely to target AFR and only turn on closed loop fuel control after the map is 99% perfect.

So, i've bought myself Elite 1500 to try out the VE method and O2 control.

I've setup the map with TPS loading, pull vacuum to the onboard map sensor.

With a largely untuned base map, with O2 control on, driving through the range, the AFR is working quite fast to reach my target map.

However, when its idling, the bank1 LTFT starts to lean off to its max -25% ignoring my target 14.5afr. It ended up going extremely lean and to counter this, i've deliberately changed my target afr to 12 to compensate the -25% leaning by the O2 control.

1.) What might have triggered this problem?

2.) Proportional, Integral, Derivative and LTFT tables, should i change them to TPS loading?

3.) Whats the best way to manage map compensation? Can this be closed loop?

Thank you very much!

Hey dude,

You ideally want your target afr map to match your main fuel table, so if you're tuning using tps, the target afr map should use tps and have the same cells. It is also advised to get your fuel map close in open loop first, before enabling O2 control, whether short or long term.

Pretty sure there is a super useful webinar on setting this up, but can't remember which one it is. So... here is a bunch of them... try 063 first.

071 | Injection Time vs Volumetric Efficiency Fuel Models - Haltech Elite 2500

089 | TPS / Alpha N Tuning - Haltech Elite

063 | Haltech Elite self learning Haltech Elite 2500

Your idle issue sounds like you have two thing fighting each other. Is your idle stable? Map try turning your O2 control off an monitoring the O2 at idle, you should also monitor what trims are being added, like intake air and coolant temp compensation.