Klondike Darol's AFR Circuits

Wideband • Narrowband
Diesel EFIE • Air Fuel Ratio Fuel Savers Circuits

D & L Engineering • Darol Mason retired from selling his
EFIE's on ebay, Darol is 83+ years old. 60 years as a
automotive engineer. He picked Hydrogen Garage Store to
continue his great EFIE leaning circuits. 3/11/17
We thank him for being able to continue such
great gas saving & ARF control product!


DAROL'S E-BOOK PAGE OF DOWNLOADS

WE HAVE PROVIDED ALL OF DAROL'S E-BOOKS ON HIS CIRCUITS
FORM THE LAST 17 YEARS OF HIS RESEARCH.

updated 11/1/2025

NarrowBand T-101 Air Fuel Ratio Control

WideBand T-101 Air Fuel Ratio Control

NarrowBand MAF/MAP (2 in 1 combo) AFR Control

WideBand Combo MAF/MAP (2 in 1 combo) AFR Control

GM V6 & V8 Frequency Based AFR Control

DIESEL EFIE/AFR Control

 

All Install Instructions are below.

 

 


DAROL'S E•BOOKS - PDF's
DOWNLOAD & LEARN FILES

Oldie but Goodie .pdf files of info. written by Darol Mason
from D & N Engineering ( 2001 till 2012)

2.5 Volt Bias on Chrysler/Dodge O2 sensors

2012 Wide band Instructions

Darol's Cleansing Instructions

Bob Boyce™ Cleansing & Conditioning Instructions

Geroge Wisemen's Post

HHO Generators

Locate your O2 sensor signal wire

MAF / MAP Enhancer

Modified T-Stat on the T-101 AFR Control Center

Modified Tuning T-101 WideBand

OBD I Vehicles

Sensor Effects and Percentages

T-Stat NarrowBand Instructions

Tuning 101 Part 1

Tuning 101 Part 2

Tuning Tips

Darol's Volo Comparison

Hydrogen Garage's Volo Comparison

Buddy's Fuel Vaporizor Instructions

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Scangauge 3 • AFR gauge monitor (Air/Fuel Ratio)

Scanguage II (clears engine codes)

Scangauge D (diesel, 6 & 9 round pin)

Air Fuel Ratio Monitor /MAF/MAP/CT & AIT temp/ RPM/ MPG
ECM Monitor Gauge • A must for these EFIE adjustments

Download the manuals for Darol's 2017 EFIE & MAP/MAP circuits :

2016 Modified T-101 / 2017 Wideband AFR

Modified Tuning 101 WB

Tuning Tips 1 / Tuning Tips 2 / NarrowBand AFR 101

Update NarrowBand

Sensor Effect %'s / GM Freq. based / T-101 for GM Package

DIESEL EFIE / Locate O2 Sensor wire 

Automotive Terms Glossary


Hydrogen Garage Store


One out of 100 HHO cell systems worked!! says
HHO Skeptic CARB/EPA Dyno Lab Consultant. 3/12

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