Home Forums Articles How To's FAQ Register
Go Back   Xoutpost.com > BMW SAV Forums > X5 (E53) Forum
Fluid Motor Union
User Name
Password
Member List Premier Membership Search Today's Posts Mark Forums Read

Xoutpost server transfer and maintenance is occurring....
Xoutpost is currently undergoing a planned server migration.... stay tuned for new developments.... sincerely, the management


Reply
 
LinkBack Thread Tools Display Modes
  #11  
Old 07-11-2020, 03:28 PM
Member
 
Join Date: Aug 2010
Location: Burlington, NJ
Posts: 770
amancuso is on a distinguished road
Quote:
Originally Posted by Big "J" View Post
Might be in left field but, what about the gas?

My 4.8 had the P0420 (Post CAT bank 1) SES recently and had to clear it a few times with my scanner. Thought my O2 sensor was going bad as well but, wasn't sure what changed all of the sudden.
Like you, it was running good and no similar issues. The only thing that was a common factor and kinda made sense, was the gas.
Oil companies went from summer blend to winter blend which, I believe contains more ethanol than the summer blend and will jack with our sensors.
So, to help narrow down possibilities I put a half bottle of seafoam in the tank and the other half used for an injector cleaning thru an intake vacuum line (brake booster hose). No more SES, better mileage and that V8 has new life at 182K.

Good Luck!
Big J, I am having the same issue with my 4.8iS 120k miles and got the P0430 twice in about 10 days. No running issues or other codes. O2's appear to be in good working condition based on analog values in INPA. I'm hoping it's a gas issue as well, as a Cat for this car is $$$$.
__________________
2004 4.8iS
Check out the BMW CCA X Chapter on Facebook - https://www.facebook.com/groups/603822583674050/
Reply With Quote

Sponsored Links

  #12  
Old 07-11-2020, 07:18 PM
Member
 
Join Date: Apr 2009
Location: Ohio
Posts: 785
Purplefade is on a distinguished road
Unfortunately it looks like Big "J" left us in 2017 with the sale of his 4.8, that said, I'm sure there's still enough brain-power on here to get you some good feedback.



I
Reply With Quote
  #13  
Old 07-12-2020, 07:30 AM
Member
 
Join Date: Aug 2010
Location: Burlington, NJ
Posts: 770
amancuso is on a distinguished road
Quote:
Originally Posted by Purplefade View Post
Unfortunately it looks like Big "J" left us in 2017 with the sale of his 4.8, that said, I'm sure there's still enough brain-power on here to get you some good feedback.



I
Thanks, I didn't get mine until 2017.
__________________
2004 4.8iS
Check out the BMW CCA X Chapter on Facebook - https://www.facebook.com/groups/603822583674050/
Reply With Quote
  #14  
Old 07-12-2020, 10:44 AM
Member
 
Join Date: Apr 2009
Location: Ohio
Posts: 785
Purplefade is on a distinguished road
Found a guy in YouTube that used spark plug non foulers to remedy a similar problem as yours, apologies, should have posted it last night when I had it, I will look for the link again this afternoon.

Basically he added a spark plug nonfouler to each O2 sensor, with a good coat of anti seize and screwed them back into the O2 bungs. His logic was that it pulled the O2s up and out of the direct exhaust path which kept them from recarboning after he cleaned them up. Cost him nearly nothing, may be worth a gamble if your issue is that bad.

Good luck and Iíll take a peek when I get a few more minutes.


Sent from my iPhone using Xoutpost.com
Reply With Quote
  #15  
Old 07-12-2020, 05:22 PM
Member
 
Join Date: Aug 2010
Location: Burlington, NJ
Posts: 770
amancuso is on a distinguished road
Quote:
Originally Posted by Purplefade View Post
Found a guy in YouTube that used spark plug non foulers to remedy a similar problem as yours, apologies, should have posted it last night when I had it, I will look for the link again this afternoon.

Basically he added a spark plug nonfouler to each O2 sensor, with a good coat of anti seize and screwed them back into the O2 bungs. His logic was that it pulled the O2s up and out of the direct exhaust path which kept them from recarboning after he cleaned them up. Cost him nearly nothing, may be worth a gamble if your issue is that bad.

Good luck and Iíll take a peek when I get a few more minutes.


Sent from my iPhone using Xoutpost.com
Thanks, that'd be great. I googles and saw how it works. My question is, should I do it for all 4 or just the pre or post cat on the bank I'm having an issue with (Bank 2).
__________________
2004 4.8iS
Check out the BMW CCA X Chapter on Facebook - https://www.facebook.com/groups/603822583674050/
Reply With Quote
  #16  
Old 07-12-2020, 05:36 PM
Member
 
Join Date: Apr 2009
Location: Ohio
Posts: 785
Purplefade is on a distinguished road
If memory serves, he just did the post cats. Havenít made it back to my home office yet, but I will look for that asap.


Sent from my iPhone using Xoutpost.com
Reply With Quote
  #17  
Old 07-13-2020, 09:41 PM
srmmmm's Avatar
Member
 
Join Date: Jun 2013
Location: DFW, Texas
Posts: 899
srmmmm is on a distinguished road
You can get these nice spacers from FCP:


https://www.fcpeuro.com/products/uni...roducts-o2pair


I'm tempted to try them myself.


2002 X5 3.0 378,900 miles
2014 428i 68,000 miles


2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles


1970 Firebird Under restoration
Reply With Quote
  #18  
Old 07-13-2020, 09:47 PM
Member
 
Join Date: Aug 2010
Location: Burlington, NJ
Posts: 770
amancuso is on a distinguished road
Quote:
Originally Posted by srmmmm View Post
You can get these nice spacers from FCP:


https://www.fcpeuro.com/products/uni...roducts-o2pair


I'm tempted to try them myself.


2002 X5 3.0 378,900 miles
2014 428i 68,000 miles


2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles


1970 Firebird Under restoration
OOO thank you. So far 200 miles and no CEL. I ran a bottle of LiquiMoly engine and exhaust cleaner through, so, we'll see.
__________________
2004 4.8iS
Check out the BMW CCA X Chapter on Facebook - https://www.facebook.com/groups/603822583674050/
Reply With Quote
  #19  
Old 07-13-2020, 10:23 PM
Member
 
Join Date: Apr 2009
Location: Ohio
Posts: 785
Purplefade is on a distinguished road
Catalytic Conveter Diagnosis HELP!

Ahh rats - my apologies, I promised a video I have yet to dig back up. Found it this evening and it isnít specific to your issue but itís very similar and may have merit with helping to fix yours.

Here that is: https://youtu.be/kmOIFMqJbWc


Sent from my iPhone using Xoutpost.com

Good luck and keep us posted
Reply With Quote
  #20  
Old 07-14-2020, 12:07 AM
Member
 
Join Date: Nov 2014
Location: SF Bay Area
Posts: 1,095
oldskewel is on a distinguished road
Quote:
Originally Posted by srmmmm View Post
You can get these nice spacers from FCP:


https://www.fcpeuro.com/products/uni...roducts-o2pair


I'm tempted to try them myself.


2002 X5 3.0 378,900 miles
2014 428i 68,000 miles


2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles


1970 Firebird Under restoration
Name:  SPP-O2PAIR.jpg
Views: 35
Size:  62.1 KB
Interesting looking design there. It makes a lot more sense than some of the more compact ones, although I realize in many cases stealth is a big factor and these are definitely not that.

My basic understanding of how they work, which may help answer some of the questions in this thread:

They only go on the downstream, post-cat O2 sensors.

The reason they work is that they create a mixing volume of exhaust gas that effectively averages out the exhaust gas coming through. So these ones shown here look good since they have a bigger volume (in that big fat elbow) in which the gas can accumulate and mix. They also appear to have a selection of orifices to choose from to tune how fast new gas will be cycled through there.

Basically fuel injection systems close the loop on air fuel ratio by switching back and forth between slightly too lean and slightly too rich. So the upstream O2 sensors will bang high/low at a controlled frequency, like 1 Hz or so. Then the cat converter is supposed to take those imperfect ratios and let them complete combustion within the cat, so that what comes out is a smooth signal, no longer oscillating up and down.

If a cat has truly lost its ability to catalyze those reactions, the gas coming out of the cat will be fluctuating high-low-O2 just like the upstream input. The downstream O2 sensor looks for this (an oscillation rather than the desired steady signal) and triggers the P0420 or P0430 to say the cat is not working right.

The extender things capture a little volume of gas, letting it average itself out and giving it some time to complete combustion, hopefully keeping the downstream O2 sensor readings steady.

The P0420 detection algorithm is notoriously inaccurate. You may find that installing an extender like this solves the code problems, and you still pass the sniffer test in a smog check - confirming that there was no true cat issue to begin with.
__________________
2001 X5 3.0i, 190k miles, AT, owned since 2014
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On





All times are GMT -4. The time now is 02:03 PM.
vBulletin, Copyright 2020, Jelsoft Enterprises Ltd. SEO by vBSEO 3.6.0
© 2017 Xoutpost.com. All rights reserved. Xoutpost.com is a private enthusiast site not associated with BMW AG.
The BMW name, marks, M stripe logo, and Roundel logo as well as X3, X5 and X6 designations used in the pages of this Web Site are the property of BMW AG.
This web site is not sponsored or affiliated in any way with BMW AG or any of its subsidiaries.