Hi-flow Race Cat

[stinky240]

Since I installed my Hi-Flow cat I have a reaccurring P0422 CEL? I know it is related to the rr 02, and it is brand new installed @ same time as cat.

Correct me if I am wrong, but it is triggered due to higher amount of CO2 of exhaust gasses. Is there a way to fool the censor?

Or I could heading in the wrong direction?

Please shed some light.

[WhiteT5]

http://www.o2sensorsimulator.com/

What brand of cat is it? I've never had a Ho2S set a code on my car with a Magnaflow.

[stinky240]

It is not a Magnaflow. I is a Race Cat used on Rally cars. I am positive on brand but can find out. My freind biulds rally cars in Aylmer Quebec and He put my exhaust on for me. Cat was brand new when installed.

[Swedish Mike]

The problem is this. A real race cat need some time to heat up to function 100%, the rear sensor pick up the "bad" cat during heat up.

Call IPD and ask them if they can adjust the sesitivity (sp?) of the rear sensor, make it less caring.

It´s possible to do that, not shut it off but make it accept more diff vs sensor one.

This kind of cat´s are used on WRC cars and fast street cars, often 80 or 100 cell. Can flow around 600hp without power loss.

/Mike

[stinky240]

If it is due to a cold cat then the cel should come up just after start-up. The P0422 code usually comes on after a highway cruise.

I don't understand why this is happening, but I will give IPD a call in the morning.

Thanks

[NoodleKnight]

I think you can just take your rear O2 sensor and hide it somewhere in the undercarriage; don't unplug it though -- this makes the O2 sensor think the cat is doing its job really well.

[Gioseppe]

I think you can just take your rear O2 sensor and hide it somewhere in the undercarriage; don't unplug it though -- this makes the O2 sensor think the cat is doing its job really well.

then you have to buy a new sensor because the heater circuit in the sensor burns out and throws ANOTHER cel because the element is always on insted of warming up with the exhaust!

just disable the rear o2. easy done.

[Swedish Mike]

If it is due to a cold cat then the cel should come up just after start-up. The P0422 code usually comes on after a highway cruise.

I don't understand why this is happening, but I will give IPD a call in the morning.

Thanks

Did you smog test it after the new cat? Maybe not working.

/Mike

[Serdar-S60T5]

hey.

if your car is pulling just the way it did before, don't worry your sensors are alright.

i've been through this.

i've done a 3'' downpipe and replaced the original cat with a 3'' straight through muffler too.

so i don't have a cat. but i still do have both sensors.

what the second sensor normally does is that it measures the heat and sends its findings to

the ecu. the ecu expects these second findings to be lower than the first sensor's findings

because the gases are supposed to lose some temp going through the cat. however, since

there's almost no drop in the heat due to the straight through muffler or maybe a high flow

race cat, the ecu gives an error code.

what you should do is, you should pull the sensor back out a little, from its original position on

your exhaust pipe so that it's not right in the middle of the pipe where the hot gas directly hits it.

this way, it'll misread the temp as lower than it really is. so you will have fooled the sensor, and

your ecu will not send an error code. ;)

[Gioseppe]

what the second sensor normally does is that it measures the heat and sends its findings to

the ecu. the ecu expects these second findings to be lower than the first sensor's findings

because the gases are supposed to lose some temp going through the cat. however, since

there's almost no drop in the heat due to the straight through muffler or maybe a high flow

race cat, the ecu gives an error code.

what you should do is, you should pull the sensor back out a little, from its original position on

your exhaust pipe so that it's not right in the middle of the pipe where the hot gas directly hits it.

this way, it'll misread the temp as lower than it really is. so you will have fooled the sensor, and

your ecu will not send an error code.

not to sound cocky/sarcastic/asshole-ish, but im pretty damn sure an oxygen sensor measures the amount of oxygen in the gas stream, not the amount of heat. if it was heat it would be called an Exhaust Gas Temperature sensor... (EGT)

you're theory is right though, about isolating the o2 sensor out of the stream of exhaust gas, but your wording behind it is incredibly wrong.

Both o2 sensors serve a different function. the first o2 sensor, located upstream of the catalytic converter measures the air/fuel mixture of the exhaust gas and reports that back to the ecu where it can compensate too add/subtract fuel. The second o2 sensor, located downstream of the cat, is there primarily to report catalytic converter efficiency.

To understand how efficient it is you have to understand how a catalytic converter works. Inside the cat is a metal or sometimes ceramic cored waffle of baffle. From the temperature of the exhaust gas, the core starts to heat up to operating temperature( 300-400 deg F) and react with the unburnt hydrocarbons (unburnt fuel) and complete the combustion cycle turning those hydrocarbons into more eco-friendly compounds.

Back to the second o2 sensor. Again, it's just there to keep a watchful eye on the Cats efficiency level (how well it burns HC's). It reads too much unburnt oxygen, it reports to the ecu that the cat has stopped functioning properly, there-fore setting a DTC in the ecu for low efficiency.

Now that that's out of the way *phew* lets talk about solutions.

1. get a cat that works right

2. place the o2 sensor outside of the exhaust stream (fools it into thinking that the cat is working PERFECTLY in every aspect, only problem is that the heater circuits burn out from constantly heating the sensor because it's not being heated from the exhaust)

3. using an o2 simulator (works for some, not for others)

4. having a reputable chip-tune company eliminate the rear o2 out of the ECU programming (euro countries don't use rear o2 sensors!)

[Serdar-S60T5]

not to sound cocky/sarcastic/asshole-ish, but im pretty Darn sure an oxygen sensor measures the amount of oxygen in the gas stream, not the amount of heat. if it was heat it would be called an Exhaust Gas Temperature sensor... (EGT)

you're theory is right though, about isolating the o2 sensor out of the stream of exhaust gas, but your wording behind it is incredibly wrong.

Both o2 sensors serve a different function. the first o2 sensor, located upstream of the catalytic converter measures the air/fuel mixture of the exhaust gas and reports that back to the ecu where it can compensate too add/subtract fuel. The second o2 sensor, located downstream of the cat, is there primarily to report catalytic converter efficiency.

To understand how efficient it is you have to understand how a catalytic converter works. Inside the cat is a metal or sometimes ceramic cored waffle of baffle. From the temperature of the exhaust gas, the core starts to heat up to operating temperature( 300-400 deg F) and react with the unburnt hydrocarbons (unburnt fuel) and complete the combustion cycle turning those hydrocarbons into more eco-friendly compounds.

Back to the second o2 sensor. Again, it's just there to keep a watchful eye on the Cats efficiency level (how well it burns HC's). It reads too much unburnt oxygen, it reports to the ecu that the cat has stopped functioning properly, there-fore setting a DTC in the ecu for low efficiency.

Now that that's out of the way *phew* lets talk about solutions.

1. get a cat that works right

2. place the o2 sensor outside of the exhaust stream (fools it into thinking that the cat is working PERFECTLY in every aspect, only problem is that the heater circuits burn out from constantly heating the sensor because it's not being heated from the exhaust)

3. using an o2 simulator (works for some, not for others)

4. having a reputable chip-tune company eliminate the rear o2 out of the ECU programming (euro countries don't use rear o2 sensors!)

i stand corrected. thanks. your explanation obviously makes much more sense.

but fyi, this incorrect info was given to me by a so-called volvo technician (didn't see his diploma or anything) working in an authorized volvo dealer in istanbul. go figure... :unsure:

[Tadek]

Hi,

I just wonder what the sensor measures, when you place it outside the exhaust streams?! As it measures O2 concentration, I wonder how this is supposed to work, since the O2 concentration is far greater outside the exhaust stream. In normal circumstances it should be 21%, which should lead the ECU to believe, the mixture is dead lean or the cat's efficiency being completely useless. Am I wrong?

Cheers,

Tadek

[copycat923]

Why not take it out of the stream and attach it to the outside of the exhaust somewhere. Stays hot so heater doesn't come on. Reads great O2 levels?

[Gioseppe]

Hi,

I just wonder what the sensor measures, when you place it outside the exhaust streams?! As it measures O2 concentration, I wonder how this is supposed to work, since the O2 concentration is far greater outside the exhaust stream. In normal circumstances it should be 21%, which should lead the ECU to believe, the mixture is dead lean or the cat's efficiency being completely useless. Am I wrong?

Cheers,

Tadek

is the afr is 14.7:1 before the cat, that's perfect combustion. the cat burns some fuel, but there is still the same amount of air in the system. comes out of the cat at 20:1. (all figures pulled out of jerk, but it's a good example)

*truth be told, o2 sensors react off the hydrocarbons and give a reading off of that... more HC, more energy, higher reading (richer). less HC's, less energy, lower reading (leaner)

Why not take it out of the stream and attach it to the outside of the exhaust somewhere. Stays hot so heater doesn't come on. Reads great O2 levels?

where is that gonna be that isn't in the pipe? pat even put his next to his turbo, the thing doesn't keep warm. trust me.

[stinky240]

Has any of you seen a, I call it a "bung adapter"? It screws over top of the O2 sensor and has a very small opening. Then the whole thing screws in the original bung.

I have only seen one of these adapters once before and it was on a street leagal Audi TT/Rally car.

If anyone knows what I'm talking about, might you know where I can get one and if you think this would solve my problem?