How does the Kit get around the CEL for no cats?
Car sounds Nice BTW...

 

they provide o2 sensor extenders that needs to be welded on

 

^^^PPE knows what there doing.

 

The O2 sensor extensions trick the ECU.

 

Many of my friends use this. I was just wondering if they used an o2 simulator like Sikky Does

 

Does the header sound opens/woot up at 3000 RPM or does it sound loud at all RPM?

 

u hear the headers at 3500 they open up i will do the video on that soon

 

they give u these

u weld it on and put in the o2 sensor in it

 

 

It's not a Sim, just an attachment (like uaaction shows). I'm not sure why it works, but it does.

(This is the point where Lobuxracer throws out a technical term like "Bernoulli's Principle", so hopefully he'll chime in. I'm interested in why such a simple modification will trick the ECU)

 

Is the O2 sensor normally in that larger diameter pipe? And you say welding on that smaller diameter pipe and putting the O2 sensor within it solves the CEL problem?

I have virtually no knowledge of cars but I have strong fundamentals in physics so I'll give it a shot if you are saying Bernoulli's equation is involved-

Bernoulli's equation is essentially a conservation of energy equation. It says that in any system with laminar, streamline flow of a low viscosity liquid (gases are usually not streamline, but treating air as a liquid is good enough for a rough estimation) and constant flow rate (not necessarily speed, as you'll soon see), the total energy of the system is conserved. In technical terms,

P + (1/2)(rho)(v)^2 + (rho)(g)(h) = P2 + (1/2)(rho)(v2)^2 + (rho)(g)(h2)

where P = pressure, rho = density (of air, in this case), v = flow speed, h = height above some reference level.

The height appears to be relatively constant throughout, thus eliminating it from both sides and reducing Bernoulli's equation in this specific system to

P + (1/2)(rho)(v)^2 = P2 + (1/2)(rho)(v2)^2

One of the assumptions that must hold for Bernoulli's equation to be true is that the flow rate must be constant throughout the entire system.

Flow rate in large diameter tube = Flow rate in small diameter tube

(Area large diameter tube in m^2)*(speed in large diameter tube in m/s) = (Area small diameter tube in m^2)*(speed in small diameter tube in m/s), or

A1v1 = A2v2 (where A = cross sectional area in m^2 and v is flow speed in m/s; notice the product yields m^3/s which, by definition, is flow rate) which is known as the continuity equation and is essentially a statement of constant flow speed within the system.

In this scenario, we're moving from a large diameter tube (where the O2 sensor, I'm guessing, is presumably located initially) to that small diameter tube (where the O2 sensor is placed afterwards). By the continuity equation, because area has decreased by some factor, the flow speed necessarily must have increased in the small diameter tube. In other words, the flow speed is higher in the small diameter tube compared to the large diameter tube as a consequence of the continuity equation.

Next, we plug this result into Bernoulli's equation - if flow speed is larger in the small diameter tube (i.e. v2 > v1), then in order for Bernoulli's equation to be true -


P + (1/2)(rho)(v)^2 = P2 + (1/2)(rho)(v2)^2

P2 must be less than P (that is, the pressure in the small diameter tube must be less than the pressure in the large diameter tube).

I'd presume that this oxygen sensor is measures oxygen levels as a function of pressure (or partial pressure of oxygen, to be precise). Lower pressure means the O2 sensor reads a lower partial pressure of O2.

My hypothesis is that installation of the PPE system results in an increase in pressure in the large diameter tube and therefore an increased O2 reading by the O2 sensor. The ECU, in turn, is programmed to light up a CEL in case O2 levels exceed a certain threshold.

By placing the sensor in a smaller diameter tube that is welded on, by Bernoulli's equation, you have increased the flow speed of air within the smaller diameter tube and therefore decreased the pressure which, in turn, decreases the O2 level sensed and read by the O2 sensor. Clearly the increase in pressure achieved by the PPE system is entirely mitigated by the decrease in pressure attained by adding the smaller diameter tube.

That's my guess, hopefully somebody with an actual knowledge of cars (lobuxracer) can chime in and comment on whether my assumptions about the O2 sensor placement were correct or not.

The physics is correct, the assumptions about the actual physical configuration of the O2 sensor was a complete guess, though.

 

I would also guess that the reduced diamater tube is not allowing the full amount of oxygen to the o2 sensor.

I think, that in the normal use of the catalytic converter, chain reactions occur to combine toxic gases with remaining oxygen molecules in the air still. This would obviously reduce the amount of pure oygen molecules and, in a perfectly working system, provide the o2 sensor with the expected voltage.

Now, when we remove the cats, more oxygen is left in the air along with all the other noxious gases. This causes a lean condtion in the o2 sensor and it throws a cel code.

By reducing the diamter of this extension and by lengthening it a bit too I would think, we have effectively reduced the amount of oxygen that is reaching the o2 sensor.

I'd bet that they tapped into the sensor to see what the voltage was in a normal system, then just played around with the right diameter and length until they found that voltage again.

 

they need to be welded on by the user? that sucks, they should come preinstalled

 

They get welded onto the stock or aftermarket midpipe.

 

sounds good!