Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Recommended Posts

Did several searches and could not find the answer if both the headers and cats can be swapped going from 3.6l to a 3.4l. For thread completeness, there several threads noting that you can put 3.6 mufflers on a 3.4, connecting to 3.4l cats. I use bypass pipes so mufflers are not part of my equation.

 

My goal is to buy a used second set of catalytic converters to be modified with new 200 cell guts, but keep the stock parts just in case I want to revert back to fully stock in the future or have trouble at visual inspection. There seem to be more 2002+ exhaust parts available and came across a 2003 set but I have a '99.

 

1. Do 3.6l cats bolt onto 3.4 headers without any mods required (no need for 3.6l headers)?

 

2. If I replace both the headers and cats from a 3.6l onto my 3.4l, will they bolt right on and all brackets fit without any mods?

 

3. If I have to do a swap back to the original 3.4l cats with 3.6l headers on, would they fit on the headers, or would I have to put the original 3.4l headers back on to get them to fit?

 

 

For reference, I pulled part numbers for both cats and headers:

 

 

Catalytic Converters:

 

3.4l  [M96.01/.02/.04] ('98-'99 / -'99  ->  '00  ->  '01-)

 

3.4l LEFT

996-113-021-53  /    996-113-021-56   ->   996-113-031-01  ->   996-113-031-02

 

3.4l RIGHT

996-113-022-53   /   996-113-022-56   ->   996-113-032-01  ->   996-113-032-02

 

3.6l  [M96.03] (2002-2005)

 

3.6l LEFT

996-113-031-03

 

3.6l RIGHT

996-113-032-03

 

 

Exhaust Manifold/Headers:

 

  3.4l  [M96.01/.02/.04] ('98-'01)

 

       3.4l LEFT (1998-2001)       3.4l RIGHT (1998-2001)

       996-111-101-52                            996-111-102-52

 

 

  3.6l  [M96.03] (2002-2005)

       3.6l LEFT                            3.6l RIGHT

       996-111-101-53                  996-111-102-53

 

  X51

     3.6l LEFT                                3.6l RIGHT

     996-111-101-40                     996-111-102-40

 

 

 

edit: Simplified part # section and added color

Edited by xmac
simplified part numbers
Link to post
Share on other sites
    You can remove these ads by becoming a Contributing Member.

While they will likely bolt up fine - I have no idea if it will pass smog tests as the later style cats got different O2 sensors.

If you decide to try it let us know if you can pass CA smog.

 

Wow, O2 sensors - I hadn't even thought of that angle for possible issues. Thanks for passing that along Loren.  Are the bung sizes are the same?  I may roll the dice on the set of cats considering the price.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Content

    • By raphael gergi
      Hey guys i uploaded a Video on youtube to show you my new Car's Exhaust Sound... the car is stock
       

       
      Let me know what you think guys or if i could do anything to make my car sound louder
    • By pike1181
      Hi guys,
       
      I've had my check engine light go on a few weeks ago and the code mentioned that the O2 sensors were running in limp mode causing the car to run rich.
       
      After taking her into the shop they informed me they found a crack in my headers before sensor 1
      and before the cats bank 2.
       
      I've got a set of GMS Ceramic Coated Headers (Can be seen here: http://www.greenmotorsport.us/servlet/the-241/GMS-987-Cayman-fdsh-Boxster-fdsh-S-Sport/Detail )
       
      The headers and cats are 1 piece and purchased 2 years ago.
       
      What do you guys suggest I do?
       
      1. Have GMS replace the headers under some sort of warranty?
      2. Wrap the headers?
      3. Have the ceramic coating grinded off the whole headers/cats, have the crack tig welded and put them back on?
      4. Have the ceramic coating only grinded off where the crack is, have the crack tig welded, and put the headers back on?
      5. Have the ceramic coating grinded off the whole headers, have the crack tig welded, have the headers wrapped, and then put them back on?
      6. Have the ceramic coating grinded off the headers, have the crack tig welded and put them back on without any heat protection?
      7. Have the ceramic coated grinded, have the cats cut off and eliminated, tig weld the crack and add an extension to the FVD exhaust.
      8. Any other ideas?
       
      Keep in mind this is my daily driver.
       
      Thank you
    • By clorigo
      Hi All,
      I am a new owner of a slightly modified 2003tt and love it. I bought it about 2 months ago and just last month the check engine light came on. I went and bought the durametric entusiast cable (which I read about here - thanks to everyone) and read a p1145. I watched the o2 sensors while the car was running and they seem good (voltage fluctuating and both bank 1 and bank 2 seem to have simular readings.) I did notice the sensors after the cat have spacers. (PPI didn't state that and I didn't know a thing about it until reading forums).
      Anyway a long story short I was reading the maintenance records of the car and noticed one mentioned a small crack in the aftermarket header (oh yeah techart headers and exhaust and I believe k24 turbos and GIAC flashed) - anyway I looked and in the collector of the bank 1 header it looked like a small black line which I assumed might be the crack.
      Would a crack in the header cause a P1145? Any other good checks? Car seems to run fine but rich at startup. Lots of power.
      Any help would be great! Thanks all!
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.