Techheads, answer me this:
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 2 1 2 LastLast
Results 1 to 15 of 21
HT4100 4.1, 4.5, 4.9 Discussion, Techheads, answer me this: in Cadillac Engine Technical Discussion; How is it that I can drive 12 miles in two ignition cycles with both oxygen sensors unplugged and NOT ...
  1. #1
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,024

    Techheads, answer me this:

    How is it that I can drive 12 miles in two ignition cycles with both oxygen sensors unplugged and NOT set any codes??

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,346

    Re: Techheads, answer me this:

    I don't know since I don't have a FSM. What are the conditions that have to be met to set an E013? What do the O2 sensor parameters display as when you are doing this...0.45V or something different? Does the "AUTO" light show while in the onboard diagnostics to show the PCM goes into closed loop or does it stay in open loop?

    I have to ask...what are you trying to do by unplugging them?

  4. #3
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,024
    Thread Starter

    Re: Techheads, answer me this:

    Both sensors read 0.45v and AUTO light stays off just as expected. E013 and E017 set when sensor voltage stays between .30v and .60v for more than 64 seconds, which it did indeed for much longer than that. Both integrators stayed at 128 and both B/L stayed at 118. Everything as expected for having no O2 feedback.

    I wanted to see how it would behave (at operating temp) on the default fuel map while running the overly rich 19# injectors. I didnt notice any difference in power, idle quality, etc although I'm sure mileage suffered quite a bit. One thing I did notice was that the temp stayed between 186 and 190 most of the time which i guess makes sense due to the extra rich fuel. Normally it's 197 to 205. I was blown away to see that no codes were set when I got home.

    The short answer to your question: Shits and giggles.

  5. #4
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,346

    Re: Techheads, answer me this:

    Quote Originally Posted by Sevillian273 View Post
    Both sensors read 0.45v and AUTO light stays off just as expected. E013 and E017 set when sensor voltage stays between .30v and .60v for more than 64 seconds, which it did indeed for much longer than that. Both integrators stayed at 128 and both B/L stayed at 118. Everything as expected for having no O2 feedback.

    I wanted to see how it would behave (at operating temp) on the default fuel map while running the overly rich 19# injectors. I didnt notice any difference in power, idle quality, etc although I'm sure mileage suffered quite a bit. One thing I did notice was that the temp stayed between 186 and 190 most of the time which i guess makes sense due to the extra rich fuel. Normally it's 197 to 205. I was blown away to see that no codes were set when I got home.

    The short answer to your question: Shits and giggles.
    Well, it's still a modified fuel map due to the Block Learn. While the block learn is only ADJUSTED during closed loop (since it's adjustment is based on the integrator which in turn is adjusted based on the oxygen sensors), it's still APPLIED during open loop. If you really wanted to see bone stock fuel map with the 19# injectors, you'd have to reset the PCM, resetting the block learn to 128.

  6. #5
    daniel58 is offline Cadillac Owners Fanatic
    Automobile(s): 58 Coupe Deville, 77 Coupe deville, 90 Deville
    Join Date
    Sep 2009
    Posts
    183

    Re: Techheads, answer me this:

    I just went round and round with my 90 Deville 4.5 (see dist 180 out post) turned out to be a bad O2 sensor. Never did set ANY codes whatsoever. Also the 19# Venom injectors I had in it are known to run very rich so that did not help things. I ran my car with the O2 sensor removed completely to check for a clogged cat and no codes were set. If you are having problems I would suggest getting an AC Delco O2 sensor and trying that.

  7. #6
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,024
    Thread Starter

    Re: Techheads, answer me this:

    I wasnt having problems... just screwing around asking for trouble After another 20 miles the codes finally did set and whats even weirder is that after getting to work today, somewhere during the ride they became history codes! Who the hell knows.... I'm not going to pursue it.

    I had a sluggish bosch sensor that never set a code either - and while trying to diagnose the problem(one bank ran too rich) I spent a long time and much headache working on the wrong side of the engine because I had ASSumed that the right bank was the one on my right when standing in front of the pulleys. Its funny how such a minor oversight (o2 sensor in your case) can cost you so much work.

    Btw as you may have read http://www.cadillacforums.com/forums...ml#post2344352 19# injectors are too big for your 4.5L

  8. #7
    daniel58 is offline Cadillac Owners Fanatic
    Automobile(s): 58 Coupe Deville, 77 Coupe deville, 90 Deville
    Join Date
    Sep 2009
    Posts
    183

    Re: Techheads, answer me this:

    Yes, unfortunately that post stating that 19# injectors are too much for a 4.5 came out 2 months after I installed the 19# Venoms.

  9. #8
    ewill3rd is offline Cadillac Technician
    Automobile(s): none
    Join Date
    Nov 2005
    Location
    WOODBRIDGE, VA
    Age
    46
    Posts
    11,062

    Re: Techheads, answer me this:

    To answer your original question... OBD I was pathetic.
    The enable criteria for the test probably are not met during your drive cycle. Those sensors were slow to heat up to reach closed loop operation. You are likely pushing closed loop back even further by leaving them unplugged. The computer is probably waiting longe for them to begin reacting. Those are also notorious for cooling off at idle and going back into open loop.
    The short story is the first thing I said above.

    You are running in open loop which will use variations of what the car has been learning in closed loop in the fuel tables so I doubt you'll notice anything other than you are tearing your emissions systems to shreds by doing that...
    Not sure what you are going for here but I doubt that this method is going to show you anything.

  10. #9
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,346

    Re: Techheads, answer me this:

    Quote Originally Posted by ewill3rd View Post
    Those sensors were slow to heat up to reach closed loop operation. You are likely pushing closed loop back even further by leaving them unplugged. The computer is probably waiting longe for them to begin reacting. Those are also notorious for cooling off at idle and going back into open loop.
    Personally, I've never witnessed this on any of my OBD-1 cars. which is all I've ever owned (still never owned anything newer than '95 ) As an example, my '90 Eldo goes into closed loop before I'm out of my subdivision and will idle all day with decent O2 cross counts...

    Averaging 21mpg around town and a personal best of 27.2 on the highway (I drive it quite conservatively), I'm assuming that the car never plays games like this.

    But interesting nonetheless.

  11. #10
    ehall's Avatar
    ehall is offline Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,487

    Re: Techheads, answer me this:

    My 85 SDV flips between open and closed loop pretty often.

  12. #11
    ewill3rd is offline Cadillac Technician
    Automobile(s): none
    Join Date
    Nov 2005
    Location
    WOODBRIDGE, VA
    Age
    46
    Posts
    11,062

    Re: Techheads, answer me this:

    I speak mainly of the single wire O2 sensors.
    The multi wire units have built in heaters to get them to closed loop faster.
    I think 95 might have heated O2s.

    The single wires rely on the heat from the exhaust to warm up and that can take some time, and at extended idle they just won't stay hot enough.

  13. #12
    Sevillian273's Avatar
    Sevillian273 is offline Cadillac Owners Connoisseur
    Automobile(s): 69 Thunderbird | 90 Seville | 89 Marquis | 72 Torino
    Join Date
    Oct 2008
    Location
    Palm Bay, FL
    Posts
    2,024
    Thread Starter

    Re: Techheads, answer me this:

    When you say 'one-wire' are you excluding the ground? My 90 has two-wire sensors, one ground and one voltage.

  14. #13
    RippyPartsDept's Avatar
    RippyPartsDept is offline Hi, I'm Chris - Please Read My Signature
    Automobile(s): 1999 DeVille "Bianca" (white/blue, VIN-Y, 160k)
    Join Date
    Sep 2007
    Location
    Wilmington, NC
    Age
    34
    Posts
    14,004

    Re: Techheads, answer me this:

    there are some single wire sensors out there - usually a purple wire

  15. #14
    ehall's Avatar
    ehall is offline Cadillac Owners Connoisseur
    Automobile(s): 1985 Sedan DeVille
    Join Date
    Aug 2007
    Location
    Southern Maryland
    Posts
    1,487

    Re: Techheads, answer me this:

    yeah my 85 is single wire, also my neighbors 93 Caprice is single wire

    3- and 4-wire are self-heating and so they do not keep the car in closed loop (other sensors like coolant temp become the laggard)

  16. #15
    drewsdeville is offline Cadillac Owners Master
    Automobile(s): 2011 Crown Vic LX
    Join Date
    Oct 2004
    Location
    Oak Creek, WI
    Posts
    5,346

    Re: Techheads, answer me this:

    All 4.X's use unheated 02's, including '95's

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting