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| Wide Band O2 |
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For those of you who don't know, there are two general types of oxygen sensors: narrow band and wide band. Narrow band oxygen sensors are accurate, but only in the very small range of air to fuel ratios that a stock car experiences while cruising. They extrapolate the ratio from the relative concentrations of hydrocarbons, nitrogenous compounds, and CO2, I think, in the exhaust gasses. Anyhoo, they are only useful when reading ratios between about 14 and 15. Therefore, to tune a car for optimal performance at wide open throttle (WOT), you need a different O2 sensor, since the ratios at WOT should generally be between 12 and 13. To read these ratios accurately, you need a wide band sensor. It is accurate when reading ratios from about 10 to 20. In addition, because the temperature of the sensor is integral to its performance, wide band O2 (WbO2) sensors are usually independantly heated by an internal element. There are NUMEROUS companies that sell WbO2 systems. You basically need two things: a WbO2 sensor and an interface to take the voltage reading from the sensor and display the proper A/F ratio. I found someone selling a Honda L1H1 WbO2 sensor for $65 instead of the usual $170-200, and an interface for that sensor that used an LCD display for $105, so I snatched that shit up with the quickness. $170 for a complete WbO2 system is a hell of a deal. When you first get the system, at least with the system I got, you have to "free air" calibrate it. Apparently, this operation compensates for the sensor aging over time. To calibrate it, attach the LCD and sensor harness, go outside, and dangle the sensor in the air. You have to have the power and groud hooked up to continue, so read below to figure that shit out. Anyway, turn the little phillip's head screw on the LCD panel all the way counter-clockwise and turn the car to "RUN" to power up the sensor. Wait until the red light stops blinking and becomes solid on. Then, slowly turn the little screw to the right until the red light JUST begins to flash really fast. Then, you're good to go. Don't fucking touch the sensor, by the way. I made that mistake. It gets REALLY hot. You can see the screw to turn (the blue thing) and the red light in the shot to the right.
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Now, on to the install. First, you have to go to an exhaust shop or a friendly welder and get them to weld an 18x1.5mm O2 sensor bung onto the exhaust piping, as close to the head as possible, but far enough away so that it's reading gasses from all four cylinders. Then just put some loctite on the sensor threads and screw it in tight. Don't do this yet, though. Keep reading. The next task is to get the wiring into the passenger compartment. The wires on the two harnesses were too short to get from where I had the sensor installed (right before the cat) to the huge grommet by the brake booster. I tried going through the shifter cable grommet, but that didn't work out, so I said "fuckit" and drilled a hole in the passenger floorboard. I cut the plugs off of each end and decided to splice the wires directly. Then I ran into a problem. Namely, there were seven wires coming off of the LCD display and only FIVE on the fucking sensor! What now?! Well, I finally realized that I could look at the plugs and determine which wires went to what. It ended up that two of the LCD wires went to nothing. I assume that this is because the LCD was a universal component and the other wires would be used in some other kind of application. Anyway, everything went together fine. Cut a slit in the rug above the hole you drilled and pass the wires through it. Mine looked like this when it was done.
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Now you need to get power to this thing. If you remove the plastic panel in the passenger footwell that sits next to the passenger's left thigh, you'll find a fuse panel. Using the fuse puller that's attached to the back of the panel you removed, pull out the 10 amp fuse circled in the picture. Stick the red wire from the LCD into one of the holes and shove the fuse back in. Then, unscrew the bolt that is in the metal brace you see in the picture. Put the exposed ends of the black wire from the LCD behind the bolt's washer and screw it back down. Finally, run the wires under the plastic paneling however you can until you're happy with its appearance. I ran mine behind all the passenger footwell panels, up through the center console, and behind the radio facade. It comes out here, right at the top corner of the radio, and looks pretty sweetocity. Anyway, have fun, and make sure to tune for 12.5-13.0:1 at WOT, bitches. Power is good.
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