P0420 Code - Page 7
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 7 of 7 FirstFirst 1 2 3 4 5 6 7
Results 91 to 96 of 96
Northstar Engines and System Technical Discussion Discussion, P0420 Code in Cadillac Engine Technical Discussion; Yeah, the labor is what gets you - the intake manifold R&R is 2.5 hours, the throttlebody is another 1 ...
  1. #91
    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
    41,626

    Re: P0420 Code

    Yeah, the labor is what gets you - the intake manifold R&R is 2.5 hours, the throttlebody is another 1 hour.

    A good wrencher can do the whole thing in the driveway in 2 hours.

  2. #92
    mustangrr is offline Cadillac Owners Member
    Automobile(s): 2003 SLS
    Join Date
    Aug 2012
    Posts
    5

    Re: P0420 Code

    That R&R you mention, does that include removing & replacing the intake manifold gasket? I ask because this same dealership told me last October that I had a leaking I/M-Gasket, and charged me for replacing it. When I returned to them 3 weeks ago with another vacuum leak, I told them I suspected the I/M-gasket they replaced last year might be the source of the current vacuum leak. They said they'd check and came back with the Throttle Body Boot story. Now I can't help but wonder if they "stiffed" me. I hate not being able to check their actual work afterwards... I can see that "knowing your mechanic and having trust" can help alleviate a lot of suspicion and distrust.

    If I may, I have another question for you Submariner409: Is it possible that the vacuum leak from the Throttle Body Boot damaged the "new, replacement" catalytic convertor that was installed 3 weeks earlier?

  3. #93
    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
    41,626

    Re: P0420 Code

    There is no intake manifold gasket in our 2000+ engines. Each port uses an individual silicone seal ring - a formed "O-ring" if you will - and they're 99% reusable. A GM dealership charges about $17 apiece for them during replacement - the entire set of 8 can be bought at a NAPA or online for $14. RockAuto is currently selling the Dorman plenum AND intake seals for $15.45 plus shipping. (Engine: intake coupling, Dorman 911010 [GM # 12555840])

    An intake side vacuum leak causes lean fuel mixtures - rich fuel mixtures are the cause of cat overheating and damage.

  4. #94
    mustangrr is offline Cadillac Owners Member
    Automobile(s): 2003 SLS
    Join Date
    Aug 2012
    Posts
    5

    Re: P0420 Code

    Thanks again for the first hand information and great illustration. I don't know much of anything about this Northstar engine, and certainly don't have any design on performing my own work. But I do like learning the mechanics and workings of the machine, and how my driving wears on it. You appear to have a wealth of knowledge and experience and I respect that of you, especially when you are so enthusiastic and cordial about sharing it. I thank you for this exchange of information.

    I took my 2003 SLS (78K miles) into another Chevy/Cadillac dealer yesterday morning and told them my SES light had been on since 8/20 and explained the history of the Cat and Plenum having been replaced recently. We confirmed the DTC was PO420, again. They took the car in for more detailed analysis. [They quoted me a standard $115 fee for the full analysis, here in Mass., which is about $30 more than the dealer in my hometown in NC charges - just an observation] They contacted me a few hours later and told me that the forward O2 sensor appears to have been repositioned during the recent repair job, and that is was located directly under the air conditioning condensation drain/or runoff. This caused O2 damage ($225 replacement) and rusting of the wire leads and 'coupling/bracket' ($150 replacement). They stated they had to order the parts from Philly o/n and that they'd have my car fixed tomorrow.

    Of course, I'm not thrilled that I have to spend more hard-earned money, so soon, but I am thankful I didn't have to replace the catalytic converter or plenum again!

    Is there a reference or link you can refer me to where I can look at detailed diagrams of the '03 Cadi engine compartment and know what I'm looking at? Maybe even a schematic of the Northstar engine broken down? I do enjoy reading reference materials and doing my own research from time to time.

    Thanks again for your info Submariner409.

  5. #95
    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
    41,626

    Re: P0420 Code

    For fingertip reading including the GM service manual, labor times, recalls, Technical Service Bulletins (TSB), Regular Production Options (RPO), diagnostic trees and illustrations, try a subscription to www.alldatadiy.com . You can directly print pages, diagnostics, parts illustrations, specification tables right from the site. There is so much info in each individual car model (Alldata is NOT generic) that you have to get used to drilling down to what you want.

  6. #96
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    70,504

    Re: P0420 Code

    Quote Originally Posted by mustangrr View Post
    Is there a reference or link you can refer me to where I can look at detailed diagrams of the '03 Cadi engine compartment and know what I'm looking at? Maybe even a schematic of the Northstar engine broken down? I do enjoy reading reference materials and doing my own research from time to time.
    Try here. When you get to the page you want, click on the blue "More Info" button for a diagram.
    http://www.gmpartsgiant.com/cadillac-parts.html

    Here's another.
    http://parts.nalleygmc.com/default.aspx

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