Wideband / Boost/Fuel/Oil Pressure

by Michael Decipha Ponthieux

Posted: 2016-11-17

Last Updated: 2023-01-04

NOTE: It IS NOT RECOMMENDED to permanentely remove or disable the EGR unless absolutely neccessary. EGR should be plugged back in and re-enabled in the tune after WOT fuel has been dialed in and the wideband is no longer wired in to the egr input.

If you do not have the ability to add in an additional bung for the wideband you have the option to disable hego2 (driver side) and install the wideband in that bung while tuning. See the Tuning Tips Write Up for more details.

NOTE: A wideband is too slow and not accurate enough to simulate a narrowband.

First you must unplug the egr valve position sensor from the EGR valve and/or the EGR flow sensor.

Installation is as simple as hooking up the widebands analog output 0-5 volt wire to your ecus egr valve position wire

The full ecu pin out is available by CLICKING HERE.

You should always source a fused 12v ignition feed directly from the fuse box. Be sure you tap into the FUSED out and not the UNFUSED in.

Verify your wideband transfer function for your wideband with the transfer below. Always verify with the manual included with the wideband and not the online info as transfers vary by model.

WBo2 - LC-1 / LC-2 / MTX-L / DLG-1 | |

Volts | Lambda |

5.12 | 1.523 |

5.00 | 1.523 |

2.50 | 1.020 |

0.00 | 0.500 |

0.00 | 0.500 |

(0.2046 * (X/12800) ) + 0.5 |

WBo2 - AEM | |

Volts | Lambda |

5.12 | 1.230 |

4.50 | 1.230 |

3.00 | 0.990 |

0.50 | 0.580 |

0.00 | 0.580 |

(2.375 * (X/12800) + 7.3125) / 14.7 |

WBo2 - AutoMeter | |

Volts | Lambda |

5.12 | 1.156 |

5.00 | ~1.275 |

4.00 | 1.156 |

0.00 | 0.680 |

0.00 | 0.680 |

0.119 * (X/12800) + 0.68 |

WBo2 - PLX | |

Volts | Lambda |

5.12 | 1.360 |

5.00 | 1.360 |

2.50 | 1.020 |

0.00 | 0.680 |

0.00 | 0.680 |

( 0.136 * ( X / 12800) ) + 0.68 |

WBo2 - B | |

Volts | Lambda |

5.12 | 1.540 |

5.00 | 1.540 |

2.50 | 1.010 |

0.00 | 0.500 |

0.00 | 0.500 |

(7.35 + ( X / 4267 )) / 14.64 |

WBo2 - C | |

Volts | Lambda |

5.12 | 1.379 |

5.00 | 1.379 |

2.50 | 1.023 |

0.00 | 0.683 |

0.00 | 0.683 |

X * 0.000010625 + 0.683 |

WBo2 - D - NGK AFX / **AFR500 | |

Volts | Lambda |

5.12 | 1.08 |

5.00 | 1.08 |

1.50 | 1.000 |

0.00 | 0.618 |

0.00 | 0.618 |

(9 + ( (X/12800) * 1.4)) / 14.7 |

WBo2 - ZT3 Ver.2 | |

Volts | Lambda |

5.12 | 1.430 |

5.00 | 1.430 |

2.50 | 1.035 |

0.00 | 0.640 |

0.00 | 0.640 |

0.158 * (X/12800) + 0.640 |

WBo2 - ZT-3 | |

Volts | Lambda |

5.00 | 1.333 |

1.50 | 1.000 |

0.00 | 0.653 |

0.136 * (X/12800) 0.653 or (2 * (X / 12800) + 9.6 ) / 14.7 |

**AFR500 when set for default gas scale.

If your transfer is not listed, post your transfer function on the Forum to be added in.

If you forget to select the wideband on the tunerpro dash keep in mind Tunerpro actively logs all transfer functions above so you can select your correct wideband transfer even after making a datalog and it will always be correct.

In all cases, after you have selected your wideband you must

then click on conversion

at the top you'll see the equation click on set

X is the EVP raw input voltage which is the widebands actual output voltage, 0 - 65535 a/d counts correlating to 0v to 5v respectively.

A wideband outputs a linear voltage based on air fuel ratio, thus one can logically infer the equation for the wideband transfer is a simple interpolation equation. The following is the basics to compute the equation.

- Max Lambda Measureable - Min Lambda Measureable =
**Z** -
**Z**/**5**=**Y**;{Max Voltage Output - Min Voltage Output (5v - 0v)}**This assumes a 0 to 5 volt range. If your wideband doesn't output down to 0 volts you will have to extrapolate the lambda values at 0 volts and 5 volts.** - (
**{Y}*** (X / 12800) ) + Min Lambda (min. extrapolated if wbo2 doesn't go to 0 volts);**Note: x/12800 is to convert ad counts to voltage.**

For Reference:

32,000 ad counts / 12800 (ad to volt conversion) == 2.5 volts

so for an equation that is 7.35 + ( X / 4267); 3.1v [stoich which correlates to ~16.6 AFR for a 2.5v stoich] the correct equation is 0.16222 * ( X / 12800 ) + 0.5

in tunerpro edit the ADX >> Values >> WBo2

then click on conversion

at the top you'll see the equation click on set

at the very tail end of the equation add

* x.xx

x.xx being the percentage your wideband is reading off (from 0.90 to 1.10)

If your wideband is reporting more than 10% off then you have the wrong transfer selected.

In all cases, if you are getting a REMOTE TUNE be sure to notify the tuner otherwise all of your corrections will be wrong.

On the dash, right click the wideband paramter and select IEGR. Now Watch the IEGR voltage closely while in closed loop AND the o2s are switching AT a stable highway speed in the higher rpm range. In your head AVERAGE the TYPICAL imaf voltage. This will be the voltage for STOICH and will be accurate so long as the o2s are switching and controlling fuel correctly. For this example the average logged imaf while at stoich cruising average about 2.8 volts.

Now find the enriched voltage while in open loop at wot having a known lambda (like say using the actual controllers gauge). If thats not feasible then you will have to force open loop at cruise and command your enrichment lambda. Again, average the typical imaf voltage in your head while the wideband is reporting a known lambda. For this example the average logged imaf while at .78 lambda reported on the gauge was about 1.5 volts.

With this data you can now interpolate the lambda at 5v == 1.372 and interpolate the lambda at 0v == 0.526

Now simply compute the new equation as outlined above.

For this example:

1.372 - 0.526 == 0.846/5 == 0.1692

0.1692 * (X/12800) + 0.526

Return Home

Jump to Forum