General Idling at 450-550 RPM

[Attilas]

Hello. This is a quick Question.I had a bad EVAP check valve which I replaced recently. Before replacing it I was idling at 750 to 900 RPM when the engine was warm. Now after replacing it is idling at 450 to 550 when I am in neutral gear and warm. Is this bad ? Normal ? No idle surges and the RPM ranges seem to be in good state when crusing in any gear. Am i overthinking this?

 

[boostdawd]

That's a bit low. Stock idle rpm should be around 750. Have u checked for leaks or adjusted your BISS?

 

[Attilas]

No I have not checked for leaks. I think I have a major exhaust leak where it was welded last summer. I get exhaust gas through the vents or so my friends say. I dont really notice a change in the quality of cabin air. Maybe they are just messing with me. Could exhaust leaks cause lower RPM ? I am not sure what a BISS is. I have not touched my engine bay yet ( Change anything mechanically ) apart from cleaning it since the car starts and runs fine.

 

[boostdawd]

Exhaust leaks will not affect your rpm but will affect the performance of your car giving false readings to the O2 sensor. The BISS is on your throtted body and allows you to adjust the air entering your engine.

Do a quick search for how to adjust your idle here and go from there.

 

[Attilas]

Okay sounds good. I will come back with Results soon. I got a test exam to enter a Program regarding Automotive Technology today. So I will be busy for a good portion of the day.

 

[Attilas]

Not sure what is going on. Idle is Back to normal. Been observing yesterday and today. Nothing was touched. Maybe its time ti get ECM Link