Results 1 to 3 of 3

Thread: WBO2 Sensor Replacement

  1. #1

    Question WBO2 Sensor Replacement

    It appears my WBO2 sensor has fouled up and needs replacement. First off my car has been running really rich since I was messing with the progressive linkage. (This little part has been the source of a lot of anguish lately). I’ve noticed my car idles really rich. Smelly, etc. I was driving and the car basically started losing power. I noticed my AFR was really low (like 6.5).

    While I was pulled over and the car wouldn’t start I called Holley support and we turned off the Closed Loop. When I started the car it would idle and run. Basically I think this means now that the ECU is only using the Base Fuel Table, and not using the Learn Table anymore. I was able to drive home, and order a new WBO2 sensor. As I was watching the YouTube video from Holley on how to install the WBO2 sensor they said that running rich can foul the sensor. Well I’m pretty certain that happened to me. Are there any other gotchas I should be aware of before I replace this sensor and ruin the new one? Thanks.

    EDIT: I’ve removed the progressive linkage and back to 1:1 and I’ve rerun the Wizard. When originally running the Wizard I had picked the wrong CAM type and my idle was really bad and really rich. After some research I realized the previous owner didn’t replace the cam. So I set it back to “stock” and the idle was much better. BUT I think it’s been too long on the bad settings and in turn I’ve been running too rich for too long and basically fouled my sensor.
    Last edited by Uncle0gre; 02-01-2020 at 12:22 PM.

  2. #2
    Join Date
    Dec 2009


    Just replace the WBO2 sensor. (Read 5th & 6th paragraphs under "Wideband O2 Sensor Notes".)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS T/W 11R 205 heads, 232°-244° duration/.623" lift/114° LSA camshaft, 12:1 C/R, TFS R-Series FTI ported intake, BBK 80mm T/B, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 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, -6AN fuel system plumbing, Walbro 255 LPH pump, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 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 M/T Street Comp tires.

  3. #3


    Great, thanks Danny! New WBO2 sensor should be showing up tomorrow. Fingers crossed.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us