Page 1 of 3 123 LastLast
Results 1 to 10 of 22

Thread: Calling all EFI Guru's, will an o2 sensor work...

  1. #1
    Budweiser
    I'm investigating the possibility of putting together a MegaSquirt (http://www.bgsoflex.com/megasquirt.html) EFI system for the flatty. Will an o2 sensor work properly with water injected headers?
    It sure would be nice to have the reliability, economy, and tune-ability that EFI has to offer.
    Thanks Guys,
    -Seth-

  2. #2
    rrrr
    Nooooo.....
    It's gotta be dry.

  3. #3
    RACER52
    nope,
    Even mine get damaged by water just by the reversion at idle with the water introduced after the o2 sensor.
    Racer

  4. #4
    BrendellaJet
    Water injecyion on a flatty? Just lose the water...

  5. #5
    Senior Member
    Join Date
    Aug 2009
    Posts
    454
    I was told that an O2 sensor would work in the heat
    crossover port, but I have a hard time believing that it would be accurate.
    there is alot of good info in that megasquirt manual.

  6. #6
    Jetaholic
    Actually...they won't work for two reasons:
    1) Water and...
    2) Weepholes will cause a false lean signal

  7. #7
    Senior Member
    Join Date
    Feb 2009
    Posts
    2,626
    For the actual operation of EFI, an O2 sensor is NOT REQUIRED, so it really doesn't matter if it will work in a wet header(which it won't). The O2 sensor's purpose in a modern road vehicle is to maintain exhaust gas chemistry in the narrow range that is required for efficient operation of a modern catalytic converter. In a performance application it can also be used simply to assist in fine tuning the system. Since I did find that the Megasquirt can be used without the O2 sensor and feedback control, you shouldn't have a problem using that particular system. Actually, I believe that most of the popular aftermarket EFI systems can be run with or without an O2 sensor.

  8. #8
    FSTFBDY
    an o2 sensor play more of a role then that. Ya it monitors the exh. gases to check the oxygen count left in it. Too much and it leans the motor out. Too little and it fattens it up.
    Thats why in any Hi performance car people send $400+ bucks on WIDE BAND o2 sensors. As you said a stock one is narrow band. (rich/lean)
    with a wide band it has a full sweet between the two for way more accurate tuning.
    My question is why do you have to have water inj. into the headers? Do hey get that hot the need cooling?

  9. #9
    Senior Member
    Join Date
    Feb 2009
    Posts
    2,626
    Thats why in any Hi performance car people send $400+ bucks on WIDE BAND o2 sensors. As you said a stock one is narrow band. (rich/lean)
    with a wide band it has a full sweet between the two for way more accurate tuning.
    Actually, I didn't say that, and as a dealership tech, all the vehicles I deal with have been using wide band sensors for many years. I do indeed know the difference. Just felt it was important to point out that EFI DOES NOT REQUIRE O2 sensors in order to function, but can still use them for tuning purposes (with the proper accomodations, of course).
    My question is why do you have to have water inj. into the headers? Do hey get that hot the need cooling?
    These days, it's getting a lot harder to find a place to run that will let you run dry headers. The LEOs tend to equate water injection(which really is to cool the headers and keep the chrome on) with muffling. Pretty much need baffles just about anywhere you go, as well.

  10. #10
    BDMar
    An O2 sensor is needed only if you are gong to run in closed loop. However, if you are going to use a high end EFI system you will want to at least tune it with a wide band O2 (UEGO). Then you can leave it in and run in closed loop where the O2 sensor will maintain the A/F ratio you have tuned for, or you can remove the O2 sensor and run it in open loop where it will simply run the map you have tuned, with no O2 sensor correction.
    In either case you CAN NOT have water in the exhaust stream where the O2 sensor is located.

Page 1 of 3 123 LastLast

Similar Threads

  1. O2 sensor
    By TollyWally in forum Gear Heads
    Replies: 9
    Last Post: 10-30-2006, 06:24 PM
  2. Knock sensor
    By jamessampica in forum Gear Heads
    Replies: 9
    Last Post: 08-09-2006, 09:27 PM
  3. Want to Run Gen 7 EFI, ? 02 Sensor
    By TJS in forum Jet Boats
    Replies: 6
    Last Post: 07-11-2005, 09:01 AM
  4. work out guru's
    By MRS FLYIN VEE in forum Sandbar
    Replies: 109
    Last Post: 02-10-2005, 03:19 PM
  5. Pressure Sensor
    By HOSS in forum Jet Boats
    Replies: 16
    Last Post: 02-07-2003, 12:01 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •