I was just curious if somebody could give a good description on how they work, what exactly is being monitored and how the sensor reads and reacts to a "resonator delete".

 

A resonator delete won't affect anything. It strictly is there to change the pitch of the exhaust to take the drone out of the sound.

EGR is for Exhaust Gas Recirculation. First, the system does not operate during idle and WOT conditions. But what it does is use some of the recycled exhaust gasses and pump them into the intake of the engine to keep the temperatures lower, which helps with emissions. While you are driving normally, the temps can get pretty high because of the leaning of the air/fuel ratio, and that can cause higher emissions, this system just keeps it in check.

The EGR valve usually gets dirty because it is using old exhaust gas, so carbon deposits can build up.

Your oxygen sensor, only the first one on the rear exhaust manifold, monitors the exhaust coming from the engine and adjusts the car if it needs to add more fuel or reduce the fuel so get a specific reading.

 

FYI - I don't have any bench marks other then the Butt-Dyno, but I think removing my resonator yielded a small performance bump (nothing huge, but it was there). But the resonator I had removed was a aftermarket one (second one to be exact) that the baffles kept rattling.

 

What affect would hollowing out the resonator have just sound? And what would that do to the 2nd o2?

 

Make it sound like you have a soup can on your car. It'll drone like crazy and since the resonator has a lot more room in it then a piece of 2.5 inch pipe like the rest of the car it'll bounce around inside and sound bad. Plus resonators tend to split down the middle b/c they're aluminum, they rust, so splitting it to hollow it will just increase that weak point.

Secondly, resonators do NOTHING for emissions, they strictly change the sound of the exhaust (help remove drone). Resonators aren't required equipment for a car, they're just put on so the cars will be quiet. So neither of your O2 sensors will be affected.

 

Mog, I believe the resonators are steel, as I've never seen aluminum rust like these resonators.

But I agree, don't bother hollowing the thing out, just have it replaced with a piece of pipe. My HONEST opinion, don't mess with it unless it has gone bad. I don't think there is enough gain to be had to spend money deleting it unless:
a. - You already had to do something as it rusted OR the baffles inside are rattling.
b. - You are taking the car to race competitions and need every HP you can possibly squeeze.

All I hear is everyone complain the exhaust is "droning" without a resonator.... I don't have a way to record how my Monte sounds, but I have the 3800 N/A with a PLOG, ZZP 2.5" downpipe and high flow cat, no more resonator and I think the exhaust is fine. It may sound a little on the tinny side, but not a big difference from what it was originally.

I have no regrets dumping the old resonator, but again, that's because my original one rusted out and I had two aftermarket ones that did not make it a combined total of 10,000 miles before the baffles inside began rattling.

 

It's made of aluminized steel is what I meant.

 

The rear o2 sensor ONLY deals with the Catalytic, since you have been asking it makes me think.

Are you talking about a resonator, or are you talking about the Catalytic Converter?

 

I have no issue with drone, and I have headers/no cat/no resonator. I can hear my car though.

 

I am talking about the cat, I just thought resonator was kinda code word for the cat, sorry for the confusion.