Disabling Emissions for test purposes

[BRN2FSH]

Hello,

I was just wondering if there is any way to disable emissions equipment such as the EGR without the Service Engine Soon light coming on. What type of emissions can be disabled for test purposes.

Thanks

 

[MikeP]

You could disconnect the oxygen sensor wiring - but the engine is going to be "unhappy" about this because this sensor reading is used to set the air/fuel ratio. It is my guess that the control module will revert to the cold engine setting (the oxygen sensor needs to be "hot" to function so when the engine is started cold, it runs on a richer air/fuel ratio until the oxygen sensor gets up to operating temperature). With the richer fuel setting, the carbon monoxide and hydrocarbon emissions will be higher (NOx lower).
Why would you want to do this?
Mike in Seattle 91XLT 4x4

 

[BRN2FSH]

Mike,

I want to do this because sometimes faulty emissions control components can cause a vehicle to run rough without setting a code in the computer. It would help diagnose engine problems if a person could disable some of the emissions control components one at a time and try to isolate a problem.

Thanks