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Thread: O2 Sensor Location Choice

  1. #1
    Join Date
    Jun 2013
    Location
    Calgary, Alberta
    Posts
    112

    Default O2 Sensor Location Choice

    Good morning Danny.
    Next question, as I continue my install at a leisurely pace... My 455 Olds has O2 sensor bungs located on both exhausts. The drivers side has the old flapper for the exhaust crossover under the intake. It functions well so my question is, should I disable the exhaust crossover by tying up the flapper? Would the crossover of the exhaust during warmup mess with my O2 readings? And if the valve is left to function as normal which location should I use for the O2 sensor.

    Thanks as always for your help. It is much appreciated.

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
    Posts
    22,927

    Default

    Quote Originally Posted by 442SCOTTY View Post
    My 455 Olds has O2 sensor bungs located on both exhausts.
    Where exactly are they located? In the collector of full length headers? Is this true dual exhaust?

    The drivers side has the old flapper for the exhaust crossover under the intake.
    If you're referring to the exhaust crossover passage cast into the intake manifold, that can remain unmodified.

    It functions well so my question is, should I disable the exhaust crossover by tying up the flapper?
    Is it an exhaust heat riser valve for a carbureted application? If so, it's no longer necessary with EFI.

    And if the valve is left to function as normal which location should I use for the O2 sensor.
    If you're retaining the heat riser valve, install the WBO2 sensor in the unrestricted (opposite) exhaust bank.
    If you've "gutted" or removed the heat riser valve, always install the WBO2 sensor in the leaner exhaust bank.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  3. #3
    Join Date
    Jun 2013
    Location
    Calgary, Alberta
    Posts
    112

    Default

    It was a heat riser for the old carb. Thank you. You've answered all of my questions, as always.

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