Purpose of Air Intake Resonator

What is the purpose of the Air Intake Resonator? When replacing the large air filter tube that goes to the throttle body I noticed the small vacuum hose leaving this air intake resonator was cracked. I've just capped the ends off for now and haven't noticed any ill effects. I'm guessing the part is discontinued. I could get the two different sized hoses and just use those barbed connectors to fix it, that is if it actually does anything.

Funny thing is I was getting the P0420 code for years. I replaced the 02 sensors a few years ago and it went away. Started coming back about a year ago and haven't seen it since. Coincidence or was it a vacuum leak?

 

It's just to catch (you guessed it) frequencies coming from the intake system make it quieter. You can remove it all together, but the line connecting to the Fuel Pressure Regulator (FRP) needs to be maintained. I made a custom Delrin plug with a hose barb to keep the connection. I can dig up a picture this morning.

 

Where does the port on the rt arrow lead to? Is that the FRP?

 

Yes- right arrow leads to the FPR.

 

Ok thanks. So then I "should" replace that hose. What would happen if I just leave it capped for now. Haven't noticed any mpg hit and ran it with a OBD scanner on it and the fuel trims seemed inline. Then again I haven't driven that far, 20 mile trips tops but going on a long road trip in a few weeks. I will get around too it, I think the hoses are 7 and 9mm or close to it and just use a barb to join them.

 

I would at least put a breather filter on the FPR tube and cap off the resonator... But just getting a new hose will probably be cheaper

 

You need to have the FPR wired in. It's maintaining the right amount of fuel pressure to the fuel rail for the injectors. You may not notice a difference in MPG, but you could have some other knock on effects from incorrect fuel pressure.

Here is the delrin plug I turned to replace my cracked resonator.

 

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