greenday is exactly right

 

like greenday say: i remove the cat in my a4 b6, and obtain 1+ psi the turbo, and remove the mid resonator with the stock back silencers and i get about only 8 hp at 5000 feets over the sea

but there is a problem: the second o2 sensor (lamda sensor) send always the message "check engine" there is no o2 simulator for the audi b6 available at the market, only for the japanese and american cars, net weekend i will fit an extension for the o2 sensor

 

ah, im not sure specifics(especially not on a b6) but would an inline resistor work? i know it will on many obd2 cars, generally it just makes the voltage equal what it did before when it had a cat, so if anyone knows what the secondary o2 sensor voltage(output duh) normally is then im sure you could make one or just wire in a resistor so that its forced to output the value you want, ill do some research and try to find specs, gotta make one for me too soon!

 

if your looking for a CEL eliminator alot of people on AW have used these and for the most part everyone was satisfied pony express just make sure the wire colors match up on the one you buy.

 

there ya go! thanks for the link!

 

how does the A4 sound with out the cat I was thinking of doing that but don't want it to be too loud

 

there is no sound increase without the cat aaronamericahall, trailboss thanks for the link, but this simulator has 2 wires per side and the o2 sensor of the b6 has 4 wires per side

 

Welcome back ImolaS4 , happy New Year.

 

so no noticable sound increase? cool i was expecting a bit anyways, well im sure my exhaust will be fairly loud when it gets built. :evil grin: 3 in exhaust, no cat, and just barely a muffler. its gonna scream.

so are people using those simulators on b5s? does anyone know the output voltage of the b6 sec o2 sensor? try emailing them, they can probibly give you what you need, maybe even a free prototype

 

Generally o2 sensor heater circuit can be simulated with 40-60Omh 20watt resistor. Most electronic parts supply stores sell the for about 1$. Normal heater o2 sensor contains two independent circuits: heater and o2 sensor. o2simulator only replacing o2sensor but not the heater. Heater can be simulated with 20 Watt 40 Ohm resistor but it becomes hot during operation and can not be combined with o2simulator in one packages.

The technology of the Bosch LSU-4 wide-band Lambda Sensor allows for accurate lambda ratio readings from 0.7 to 1.4 and beyond, bosch lsu-4 wide band oxygen / lambda sensor circuit diagram. This wide lambda range is possible, because the closed loop control unit uses an almost linear I-Pump current.

The wide-band sensor uses two different cells, an O2-ion pump-cell and a sensor-cell (Nernst type).
The pump-current pumps enough O2-ions into the measuring chamber, which is shared by both cells, until the sensor cell shows 450 mV (Nernst cell lambda = 1) across it's electrodes.

The lambda ratio is now almost linear proportional to the measured pump current.