StylinTLS

I remembered a while back that there was a post about being able to bypass it with a capacitor attached to the positive wire. Anyone know if it's been done? And any details about it? Or was it just someone shietting us? :p

Mr.T

Do a search in the CL forum. I think so dude did it there. Anyways you going to the meet on Sunday?

Mr.T

StylinTLS

Nah...the 7:30am time kills it for me. I'm in the mood to socialize with the females so Imma be ravin/clubbin Sat night.. :p Take pix and tell me about Sun tho..

Edward'TLS

The powertrain control module (PCM) uses the O2 sensors to monitor the level of residual O2 levels inside the exhaust gas, and increases or reduces fuel delivery by varying the injectors' pulse width. You cannot just substitute the signal with some dumb values, because it will affects the drivibility of the car.

A while ago, my family's Accord has a failed O2 sensor. The car would shaked and bucked whenever I applied more gas and would not accelerate very well. My wife's family's Volvo would not go above 30km/h with a failed O2 sensor.

However, you can leave the sensor wire disconnected. If the PCM does not sense any activity in the sensor wire in the closed-loop mode after the water temp is high enough, it will light up the dash check-engine light and go to a default mode. In this mode, the PCM will substitute the O2 sensor reading with its built-in default values, and allows the engine to run as in the open-loop mode. But then the engine will pour out tons of excess emissions. Unfortunately, some car will go to a limp-home mode instead, as in the Volvo, and won't let the car go above a preset low speed to prevent any damage.

I have no idea what mode our TL will go to if you disable the O2 sensor(s).

VTEC Animal

Yeah, why on earth would you want to disable the o2 sensor when it'll make performance worse?

Edward'TLS

Please note that I do not encourage anyone to defect the emission control systems in cars. Don't mess up the air we are all breathing into our bodies.

The performance may, in some cases, be better when the O2 sensor is disabled. A modern engine with electronic management computer has two modes of operation, closed-loop and open-loop. When the engine is cold or not up to normal operating temperature, it stays in open-loop. This means the engine is not looking at the readings from some sensors, particularly O2. It substitute them with the values inside the ROM or flash memory. The engine will run rich and emit loss of harmful emission. Idling rpm is high. Ignition timing will change. Depending on the PCM program and the default map values, some engines will run stronger in this mode.

When the temp is normal, the engine will go into closed-loop mode. In this mode, the PCM is analysing all the sensor readings and adjust fuel and ignition timing optimumly to maintain emission to the lowest allowance level. This rarely equate to maximum performance.

By disabling the O2 sensor, the PCM can be forced to the open-loop or a default mode, and again depending on the engine computer, may allow for better performance at the price of our environment.

asif2002

Hey,
I was thinking about removing my Catalytic converter since there is no more emmisions in Florida. Could somebody tell me simply how to do this. Do I just take it to a shop that would weld off my catalytic converter and get a long screw driver and bash out the honey comb inside the cat. And what would I do with the O2 senser. Would I just leave it in there or would I be able to bypass it with a capacitor attached to the positive wire. I dont know if i am going to do this but i just want to know about it and what type of performence gain I would get. Thanx

2001TL4KCdude

Removing a converter from a vehicle is a violation of the Clean Air Act and you can be fined a penalty, regardless of which state you reside.
$0.02 on catalytic converters
A catalytic converter is a device located in the exhaust system of all cars and most light duty trucks produced since 1975. It chemically converts pollutants like carbon monoxide, hydrocarbons, and nitrous oxides into harmless substances like carbon dioxide, nitrogen, and water vapor. There are three (3) types of converters in use today. The 2 way, or oxidation converter, controls carbon monoxide and hydrocarbons. The 3 way converter controls the same pollutants as the 2 way but also controls oxides of nitrogen. The last converter is the 3 way converter with air tube. It does the same thing as the 3 way converter, but uses air injected through the pipe to help the chemical reaction. The proper replacement converter must be installed and can be identified by the vehicle's emission label located under the hood.
According to the Clean Air Act, if a vehicle is less than five years old and has less than 50,000 miles on it, it must be replaced with an original equipment converter. If this is the case, the repair will usually be covered by the car's warranty.