Decat pipe and emmisions?

[SteveJ]

so what is he using as a signal buffer?

Supplied with his turbo kit - not sure where it originates or what is in it (looks a bit like the 3rd O2 conditioner you can buy for removing the final cat, only bigger and with more wires sticking out)

[markiii]

interesting, have to see if he will take it apart and look.

[Tem]

Doesn't the PPE manifold require just that?

Using only one O2 sensor to feed both inputs...it seems to be working pretty well for guys @ SC.

[Anonymous]

Well i'm not sold on the theory, but it's the best so far. The O2 mod has been circulating on spyderchat for ages and Monkey Wrench now include the wiring mod in their instructions with no conditioner used with any other application i've read about.

[markiii]

Doesn't the PPE manifold require just that?

Using only one O2 sensor to feed both inputs...it seems to be working pretty well for guys @ SC.

correct though I'm not sure what they provide, perhaps adam can comment having installed one?

[Tem]

Doesn't the PPE manifold require just that?

Using only one O2 sensor to feed both inputs...it seems to be working pretty well for guys @ SC.

correct though I'm not sure what they provide, perhaps adam can comment having installed one?

Looks like they provide an "extension wire" and "crimping connectors":
 m http://www.spydermagazine.com/2003/Nov/ppe/ppe.htm m

[Anonymous]

Yeh no conditioner or signal buffer there.

[mph]

There is, under some heat shrink stuff. See the very last piccy from the link above, then follow the arrow marked '1' to the top loop of the cable. There's a small rectangular box of tricks inlined in the cable. Some basic multimeter readings indicates that it's not just a cable being split but something a bit cleverer.

[Jap GT300]

Looks to me as though they had just split the cables.  I have the O2 stuff off the car so I can take a couple of snaps tonight and take a closer look.

I never managed to get the setup to work.  It always produced a CEL!

[DAZ400]

The Catalytic Converter
 
A device incorporated into the exhaust system of an automobile that reduces the amount of pollutants in the automobile's exhaust gases.
A catalytic converter consists of an insulated chamber containing a porous bed, or substrate, coated with catalytic material through which hot exhaust gas must pass before being discharged into the air. The catalyst is one of a variety of metal oxides, usually platinum or palladium, which are heated by exhaust gas to about 500º C    (900º F, 737 K). At this temperature unburned hydrocarbons and carbon monoxide are further oxidised, while oxides of nitrogen are chemically reduced in a second chamber with a different catalyst. Problems with catalysts involve their intolerance for leaded fuels (lead-free gasoline must be used otherwise the beads in the catalytic converter will become coated with lead and cease to function properly) and the need to prevent overheating.

However because of the conversion of carbon monoxide to carbon dioxide it therefore causes an increase in greenhouse gases and in the process of removing toxic gases to less non-toxic gases it causes an increase in the greenhouse effect.

   This reaction is oxidisation of the hydrocarbon.

     This reaction is oxidisation of Carbon monoxide.

              This reaction is reduction of Nitrogen oxide.

By using both a reducing and oxidising catalytic converter, we can lower the activation energy for the HC, CO and NO so that they more quickly react to form less noxious products.



The reactions that occur in the catalytic converter are due to a catalyst. The catalyst is in a separate phase to the reactants is said to be heterogeneous, or contact catalyst. Contact catalysts are materials with the capability of adsorbing molecules of gases or liquids onto their surfaces.

Other Products

However due to the conversion of these oxides into dioxides it causes other pollutants to be emitted in the exhaust of the car. Though Nitrogen monoxide (a chemical which attacks the ozone layer and contributes to the formation of photochemical smog) and Carbon monoxide are extremely toxic since these are converted by reduction and oxidation into other gases, the Nitrogen monoxide is turned into harmless Nitrogen and Oxygen gas (N2 O2) so there is no problem with the conversion of Nitrogen monoxide but Carbon monoxide gives of a less toxic (to humans) product in the form of Carbon dioxide (CO2) which is absorbed by plants in photosynthesis but this Carbon dioxide is a major cause of the greenhouse effect – where the greater the amount of Carbon dioxide molecules in the atmosphere the warmer the Earth gets. A prime example of what could happen if this type of exhaust conversion is used is the planet Venus; this has a runaway greenhouse effect and has a surface temperature of over 400º C .

Along with these products from the catalytic converter there are other toxic products which are Sulphur dioxide (SO2), which is the cause of acid rain and Hydrogen Sulphide (H2S) which is a very toxic (poisonous) chemical.

Effect of Temperature

The lowering the temperature causes the reactions of the Hydrocarbons and Carbon monoxide with Oxygen occur more often and would also stop the formation of Nitrogen monoxide from Oxygen and Nitrogen in the engine. This is however hard to do and so complicated cooling systems are applied to get the best performance of the fuel and the conversion of waste products.

Composition of exhaust

Exhaust Component (%)
 
 Driving Mode
 
 
 
 
 Idling
 Cruising
 Accelerating
 Decelerating
 
Carbon Monoxide
 5.2
 0.8
 5.2
 4.2
 
Hydrocarbons
 0.075
 0.03
 0.04
 0.4
 
Nitrogen monoxide
 0.003
 0.15
 0.3
 0.006
 

So at anyone mode of driving one of the exhausts is being produced faster than the other. On average the cruising mode would be probably the time when the least amount of gases is being produced.

Catalytic converter substrates

A substrate is a substance on which some other substance is absorbed or in which it is absorbed.

Catalytic converters are used to reduce the amounts of nitrogen oxides, carbon monoxide, and un-reacted hydrocarbons in automotive emissions. (Catalytic conversion requires a precisely balanced air-to-fuel ratio, hence the need for oxygen sensors such as those described in conductive ceramics: Oxygen sensors to aid in feedback control of fuel injection.) In dual-bed converter systems the exhaust gases are first reduced in order to eliminate the oxides of nitrogen; then they are oxidized with added air in order to eliminate carbon monoxide and unburned hydrocarbons. In more advanced three-way converters individual catalysts accomplish reduction of each species simultaneously.

Catalysts are either platinum-group metals or base metals such as chromium, nickel, and copper. Platinum-group metals or noble metals are any of several metallic chemical elements that have outstanding resistance to oxidation, even at high temperatures; the grouping is not strictly defined but usually is considered to include rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold. Silver and gold, which with copper are often called the coinage metals, and platinum, iridium, and palladium comprise the so-called precious metals, which are used in jewellery.

In base-metal catalysts the active surfaces are actually ceramic oxides of the metals. Because platinum metals are extremely expensive, they are deposited on ceramic catalyst supports as salts and then reduced to finely divided metal particles.

For efficiency of conversion, extremely large surface areas are required. These are accomplished by ingenious micro-structural engineering of the ceramic support structure. Two types of structure are made pellets and honeycomb monoliths. The pellets are porous beads approximately 3 millimetres (1/8 inch) in diameter. With a single pellet having up to 10 square millimetres of internal pore surface area, one litre of pellets can have up to 500,000 square metres of support surface. The pellet material is often alumina (aluminium oxide, Al2O3). High internal porosity is achieved by carefully burning off the organic additives and by incomplete sintering. Honeycomb monoliths have 1,000 to 2,000 longitudinal pores approximately one millimetre in size separated by thin walls. The material is commonly cordierite, a magnesium aluminosilicate (Mg2Al4Si5O18) known for its low thermal expansion. The extruded cordierite structure is coated with a wash of alumina, which in turn supports the platinum catalyst particles. The surface area of the monolith is typically in the range of one square metre; however, this figure must be multiplied many times because of the porosity of the alumina on the surface.

Monolith supports are much more expensive than pellet supports, but they cause a smaller pressure drop in the exhaust system. Both types of catalyst support, because of their inherent friability, are susceptible to vibrational degradation. Containment of the supports is also difficult. A good seal must be achieved and maintained without imposing external stresses on the friable structure.

Conductive ceramics: Oxygen sensors

Schematic diagram of a zirconia oxygen sensor used to monitor automobile exhaust gases. The sensor, approximately the size of a spark plug, is fitted into the exhaust manifold of an automobile engine. The thimble-shaped zirconia sensor, sandwiched between thin layers of porous platinum, is exposed on its interior to outside air and on its exterior to exhaust gas passing through slits in the sensor shield. The two platinum surfaces serve as electrodes, conducting a voltage across the zirconia that varies according to the difference in oxygen content between the exhaust gas and the outside air.

[heathstimpson]

Bloody hell Darren are you a scientist or something mate  s:?: :?: s:?:

[Anonymous]

Looks to me as though they had just split the cables.  I have the O2 stuff off the car so I can take a couple of snaps tonight and take a closer look.

I never managed to get the setup to work.  It always produced a CEL!

If you use only one O2 precat sensor ( as with PPE header i.e.) , you have to connect the 1st O2 sensor to 1st connector  ( that on the England driver side). How to wire the 2nd connector? Prolonge blu and withe wires of the first one. Naturally now, the signals to the ECU will be the same for all two . Also the other 2 black wires ( heater circuit ) must be prolonged but you cannot connect directly to 2nd connector. Before  you have to solder a resistor ( 20 Ohm 10-15 watts ) between them and then connect them to 2nd connector. Attention that the resistor will become hot running. This is the contents of small rectangular box n° 1 of pic above.

[DAZ400]

NO. You do not need a resistor, why simulate the heater load for a sensor that is not used it is pointless all it will do is use power and generate heat. All you need is to connect the black wires which are the signal wires together for the two inputs and just use the one sensor.

[DAZ400]

Heath amiture Scientist found the infor on the net.......  s:roll: :roll: s:roll:

[Anonymous]

NO. You do not need a resistor, why simulate the heater load for a sensor that is not used it is pointless all it will do is use power and generate heat. All you need is to connect the black wires which are the signal wires together for the two inputs and just use the one sensor.

To avoid a CEL code P0141 ( Oxygen sensor Heater circuit malfunction). Resistance between two black wires has to be between 11-16 ohm at 20° C.

[DAZ400]

OK fair enougth you learn something new every day......

[DAZ400]

Had my new exhaust fitted today.

Found I had destroyed the origional CAT.

And to top it off melted the resovoir for the SMT Hydrolichs and the undertray caught fire on the way home bit of a bummer day..........

Note to self get fuel pump in and get it tuned properly before I cook anything else.........

  s:D s:D     s:cry: :cry: s:cry:     s:cry: :cry: s:cry:     s:cry: :cry: s:cry:

[Anonymous]

Been a shite day for you mate but look on the brightside, it could of been alot worse, if you hadn't got the fire out as early as you did, you'd of been sat at the roadside watching your pride and joy burn   s:cry: :cry: s:cry:  

Without adding the fuel pump mate, you'll be able to add some fuel through the range and stop her running so lean, and hot.

[markiii]

for anyone interested, heres the main cat, and the replacement pipe I had made up.

[markiii]

for info I've edited the original post with comparative values taken with all cats in place.

[MRMike]

I'm considering the pro's and cons of removing all the cats..the apparent hole of lost torque v the top end performance that you noted Mark.  One of the things that's bothered me though is that there didn't seem to be a fix for the CEL.  Mark what was the CEL ? Was it presumably too much O2?

Just noticed this little device which might cure the problem.   m http://www.badtoys.ch/get.asp?template= ... arameter=2 m ¦32¦16¦1

(Bottom of page)

Presumably it works by tricking the ECU into thinking there is less O2? (If I'm correct in my assumption that the 02 was too rich in the first place..)

[markiii]

the cel is a main cat below efficiency error.

i.e it's not working very well, bo kidding thats because it's not there  :-) :-) :-)

basically the ECU compares teh 02 reading from before and after the main cat, and knows their should be a difference in the ranges of x to show teh cat is working.

It won't hurt if you just do nothing. except if a real cel appears you won't see it.

PPE do such a simulator for sale with their 4-1 manifold, I got mine from them for teh princly sum of $15

with regard to teh torque hole, you can improve overall performance by removing all cats, but to avoid teh downsides (lost torque) you need to change the runner lengths and pipe dimensions to optimise flow.

just decatting won't acheive that.

[kanujunkie]

guys can anyone remember the wattage of the resistor that you need to fool the ecu into thinking the 02 sensor is working ok. On my C2 install we connected the 2 main 02 sensors together(bank 1 sensor 1 & 2) and moved the 3rd 02(bank 2 sensor 1) to the RHS of the engine bay. But the heater circuit on the old bank 1 sensor 2 has a 15ohm 15watt resistor in it and still throws a Cel. Mark and myself thought that was the reason at the time but can anyone confirm that it should be different??

[spit]

15ohm is about right - my functioning O2 used to read at 14.

As for wattage, I've had 10W ceramics for 8 months now and they're holding up fine but do get v hot. Got a couple of 15Ws to strap in - but if it aint broke.....

I'm sure you've confirmed that its a heater circuit fault? The only thing that occurs to me would be to check your soldering between resistor and the two black harness wires. Mine would break down under load/heat and throw a CEL but since re-tinning and soldering its been fine.

[kanujunkie]

Mark confirmed it was the heater circuit at fault, could always be a dodgy resistor then, i'll get another one and try again, solderings fine BTW