'94 Seville SLS High HydroCarbon output
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 29
Cadillac Seville / Cadillac Eldorado Forum Discussion, '94 Seville SLS High HydroCarbon output in Past Cadillac Vehicle Discussion; Trying to get my Seville past Cali Smog test and have 2 issues: 1) After changing spark plugs with AC ...
  1. #1
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    '94 Seville SLS High HydroCarbon output

    Trying to get my Seville past Cali Smog test and have 2 issues:

    1) After changing spark plugs with AC Delco's (which, btw, is a miracle cure for rough idle) and cleaning EGR valve, got the HC #'s from 1200-1300's to 150-200's. Wondering what else I can do to get the HC #'s down to 100 or lower. Mechanic says the cat converter is probably shot after running that high for so long. Possibly, but would rather try something else cheaper than a cat converter. PCV perhaps?...I don't know.

    2) Keep getting a P039 code that causes the SES light to come on and automatically fail the Smog test. Read here that there may be a software upgrade for this as I dont feel any problems with the tranny. Called the Caddy dealer and the service tech I talked to wasn't aware of any software update for that year. Havn't yet tried cleaning the sensor connector to the tranny but is on my to-do list. Will let you know how that turns out after I figure out how to get my fat butt under the car.

    I've been impressed with everyone's input here after a week of reading/researching....lets see how y'all do with this problem!!

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Ok ok, so after some more reading, it looks like I need to get a PROM to fix my P039 code. Where do I get one of these and where does it go?

  4. #3
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,806

    Re: '94 Seville SLS High HydroCarbon output

    P039 (E039) ..... Torque Coverter Clutch/Viscous Converter Clutch Engagement Problem
    Usually that is a bad solenoid inside the trans. $50 part, $2000 deep in the trans. Cheaper to clear the code and drive it in 3rd for a week before the test.

  5. #4
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Thanks Ranger for your reply....

    The only reason I'm having a hard time wrapping my brain around your answer is that the tranny seems to be fine. Nothing noticeable by driving it anyways. And just curious about what you said; are you saying to leave it in 3rd and drive on the highways, etc and what does this do after a week before testing?

  6. #5
    Krashed989's Avatar
    Krashed989 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 Eldorado, and a 99 ETC
    Join Date
    Sep 2004
    Location
    Hilo, Hawaii
    Age
    27
    Posts
    3,887

    Re: '94 Seville SLS High HydroCarbon output

    Quote Originally Posted by Jake35 View Post
    ... Mechanic says the cat converter is probably shot after running that high for so long...
    umm... What?...

    Hydrocarbons = fuel
    More of them = a rich condition
    Cat converters die out faster in lean conditions than rich conditions
    Lean makes it hot, even red hot. Have you ever spilled fuel on yourself. It feels cold right? That's how it feels to the cat converter too. Even when the fuel burns in the cat (which is what the cat is for), it burns at a cooler temp when its rich in fuel.

    So to sum it up;
    More hydrocarbons = a longer life for your cat converter
    Too little hydrocarbons (a lean condition) = a shorter life for your cat converter
    The mechanic might be trying to get some moolah from you. However, your cat converter might just be old and becoming less efficient. It's job is to burn the leftover hydrocarbons, so there should be close to 0 out of the end of the exhaust.

  7. #6
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,806

    Re: '94 Seville SLS High HydroCarbon output

    You won't notice much difference. An automatic transmission has a little slippage unlike a standard trans that locks the engine to the trans. The TCC does just that. It locks the two to stop the slippage and give a little better mileage. Hold your speed steady (above 41 MPH) and just touch the brake pedal as if to disengage the cruise. The tach should jump by 200-300 RPM when the TCC disengages (if it is working). If you do not see the jump, then it is not engaged and in the failure mode. It will cost you about 1 MPG. It should only engage in 4th gear so leaving it in 3rd does not reset the DTC and give the PCM a week to pass all the readiness tests. If you clear the codes and go right in for a test, they can tell and you'll fail because the readiness flags will set. Uncle Sam already figured we'd try clearing codes before the test.

  8. #7
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Awesome explanation Ranger...thanks again! Will do.

    Krashed...Im still at a loss as to what would be causing the hc's to be high. Ohm'd out the coils...(with ohm meter in 20k position...dont know how to decipher/translate) 2/5 @ 5.79, 8/3 @ 5.78, 4/1 @ 5.77 and 6/7 @ 5.91. Spark plug wires ohm'd out between 1.32 and 4.06. Not opposed to replacing wires but at this point dont know if thats gonna help burn the gas anymore.

    Any ideas?

  9. #8
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Also just read some explanation about Cold Carbon buildup and the remedy is to go out in 2nd gear at WOT to 70 and back....I dont know if this is gonna help, but it sounds fun as hell!! Will check back when I return

  10. #9
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Just got back from 2nd gear WOT to 70...blew a bunch of smoke out the tail pipes...couldnt tell which color because it's dark. But in the process threw a P042, which seemed to clear after normal driving. Maybe that points to the cat converter after all?

  11. #10
    Krashed989's Avatar
    Krashed989 is offline Cadillac Owners Connoisseur
    Automobile(s): 94 Eldorado, and a 99 ETC
    Join Date
    Sep 2004
    Location
    Hilo, Hawaii
    Age
    27
    Posts
    3,887

    Re: '94 Seville SLS High HydroCarbon output

    P042 = Left (towards the front of the car) bank O2 sensor signal lean.

    That could be why you're getting more hydrocarbons. If the sensor sees that it's lean, the PCM will make the injectors stay open slightly longer to give it more gas.

    Let me see if I can get you something for that code.

    Edit: Here ya go:


    PD32 is in the "PCM DATA?" menu in the on board diagnostics.



  12. #11
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Just finished troubleshooting....

    PD32 fluctuates above .3v. Referring to NOTE and checking Snapshot Data Parameters, PD38=160 and PD39=113. Dont know if that determines both banks were lean or not or how to check condition that would cause lean engine operation.

    I mentioned last night that the SES seemed to clear itself after returning to normal driving patterns. While checking the above parameters at idle, the SES light came back on. (I never cleared the p042 code last night or today)

    I dont know if this is an apples to oranges comparison but my wifes Ford Windstar required replacing o-rings under the valve cover to eliminate a p071 and p074 code (left/right banks running lean). My SLS has a nice oil leak going on in the back (1,3,5,7) and Im assuming its a valve cover. When I pull the spark plug on #5, it has oil around the threads... Your thoughts?

  13. #12
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    44,989

    Re: '94 Seville SLS High HydroCarbon output

    The cam cover/spark plug wells are sealed by O-rings which tend to weep over time. Oil on the threads and/or the metal shell of one or more spark plugs is fairly common.

  14. #13
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Thanks Sub..thats good to know. I guess my question is if the valve cover gasket/o-rings are leaking oil, will that cause a lean condition? I'm debating replacing the gasket/o-rings anyways, just to eliminate the drops in the driveway, however, my ultimate goal is to get this thing pass the California Smog test so I can sell her.

  15. #14
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,806

    Re: '94 Seville SLS High HydroCarbon output

    No, the cam cover gaskets or O rings shouldn't cause a lean condition. They are not as easy to replace as you might think. No room to lift the rear one so the engine has to be lowered or tilted. Front one has the water pump drive pulley attached to the intake cam and has to be removed. On a '93/'94 I'd look closer at the intake manifold cover gaskets. Those could cause a lean condition and are MUCH easier to change.

  16. #15
    Jake35 is offline Cadillac Owners Member
    Automobile(s): 1994 Seville SLS
    Join Date
    Oct 2009
    Posts
    14

    Re: '94 Seville SLS High HydroCarbon output

    Just got back from having it Smog Tested. Failed...but not by much. I guess they don't require it to be dyno'd....they just do emissions. Here's the results:

    RPM....%CO2....%O2................HC (PPM)..................CO (%)
    .......................................Max....Ave. ..Measured...Max....Ave....Measured
    649..........13.0......1.8........100.....17.......112........1.00....0.0......0.27 Failed
    2432........13.5......1.0.........130.....12...... ..24.........1.00...0.10.....0.35 Pass

    So its just at idle that my HC's are too high...Im stumped

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