Snypr18

Hi guys, I noticed that there is just a hole where my "EGR sensor" should be. The plug where it connects appears to have been capped off with a professional-looking resistor plug. Im guessing the sensor went bad and the previous owner just capped off the wire to get rid of the CEL. Everything else related to the EGR system is intact. Is this something I should replace, or at least plug the hole? What does this sensor do, exactly? The truck passed smog here in April, so it seems like not much is going wrong as far as emissions is concerned.

...Anyone here have strong opinions one way or the other on removing the EGR system entirely?

millball

Not all emissions regimes require that EGR temp sender input.

That sensor merely detects temperature, so as to tell the ECU that exhaust gasses are actually flowing thru the EGR.

All of the wiring harnesses were made to accept that sensor and when it was not required, the factory termination plug you have was installed.

No worries, It likely left the factory like that.

I bet it's Federal emissions compliant, not California...

Snypr18

Ohhhh I see. This was originally a PA 4Runner, so that makes sense. Thanks millball.

scope103

I'm guessing the circled boss on the EGR valve is not drilled out or tapped, as it would be in a California model. Millball's description is correct; if the valve stops working for some reason, there is no flow to the intake and a temperature sensor can detect that.

California or Federal, the EGR system does a great job of reducing NOx emissions. (NOx, when combined with moisture in the air, forms Nitric Acid. Which you then get to breathe!) The EGR reduces the peak combustion temperatures slightly, which keeps atmospheric nitrogen from combining with oxygen in the cylinder. The EGR doesn't affect performance or fuel economy, though the slight reduction in peak temps may extend engine life.

Keep it. You're the one breathing the air you would otherwise pollute.

1stgen88t4r

My CA 92 truck w/3vze has a sensor in that place.