Fooling the ECM on the cheap Harley Twin Cam Discuss Fooling the ECM on the cheap in the Motorcycles forums; nightrider has an article with an arrangement that uses 2 resistors crimped into the O2 sensor cable. Essentially, thet create a voltage modified circuit, so instead of 14.7 AFR the ...

[BluesFan]

nightrider has an article with an arrangement that uses 2 resistors crimped into the O2 sensor cable.

Essentially, thet create a voltage modified circuit, so instead of 14.7 AFR the ECM sees 14.2, which the ECM wants to be 14.7.

Thus the ECM is always trying to richen the fuel air mix. This supposedly takes the edge off the lean.

For $10 or so at Radio shack for 4 ristors and some crimps and heat shrink.

(Gotta crimp, can't solder the cables, article explains that the O2 sensor vents/breathes through the cable.)

So whatta you think?

[aceharleywrench]

It might work,but what size resistors?2ohm? 4ohm? I don't think I'd wanna be the guinea pig on this one.

[Tbone]

Essentially you wind up with IED's.

O2 Sensor Inline Enrichment Device

Already built. Plug and play.

[BluesFan]

Same guys

They've updated their site,

How to Richen Closed Loop EFI | Motorcycle Performance Guide

This used to show, I think, a 250K and 150K resistor.

[frisco-rigid]

Blues

Very cool trick, I've never heard of it before..
I'll look into applying it to my car cuz I've never succeeded in fooling it's comp cuz that dang 02 sensor always tattles on me..
Thanks for posting the link..! & T too..



Hey,, cool sig Daddio.. Yeah Baby.!

[Twinpeaks]

I have heard about this before and believe it works, however is there a reason you are running too lean? Is a proper map not a better option?

[unclepsycho]

Originally Posted by Tbone

Essentially you wind up with IED's.

O2 Sensor Inline Enrichment Device

Already built. Plug and play.

holy crap! I thought you were talking about and IED= Improvised Explosive Device....!

Then I read some more and found out what you really meant....Whew!!

[BluesFan]

The only thing "wrong" with the existing map and the ECMs adapability is that it aims for 14.7 AFR.

Making the ECM think it is too lean makes it run richer, just that little tad that it needs.

I'm gonna run it by some smart folks at work and see what they think.

Then I'll consider a run to Radio Shack.

[Tbone]

Originally Posted by Twinpeaks

I have heard about this before and believe it works, however is there a reason you are running too lean? Is a proper map not a better option?

Talking stock ECM here. These are to go inline on the stock Ox sensors on stock ECM. No fuel management device like SERT, or SEPT or PCIII. Stock 2006 Dynas and 2007 and up all EFI are all on the lean side to meet EPA requirements of emissions.

[Twinpeaks]

Originally Posted by Tbone

Talking stock ECM here. These are to go inline on the stock Ox sensors on stock ECM. No fuel management device like SERT, or SEPT or PCIII. Stock 2006 Dynas and 2007 and up all EFI are all on the lean side to meet EPA requirements of emissions.

True with most stockers but the stock EFM can be easily and properly remapped to negate the EPA restrictions. You can run as rich/lean as you need be. However, this is a - dollar wise - easy way out huh!?