× A place to ask questions about specific ScannerDanner videos or testing procedures listed in ScannerDanner's Engine Performance Diagnostics book

Post catalytic O2 sensor

  • Aqeelalobaidi1980
  • Topic Author
  • Offline
  • New Member
  • New Member
More
10 Dec 2019 09:20 #35697 by Aqeelalobaidi1980
Post catalytic O2 sensor was created by Aqeelalobaidi1980
Hello mr. Danner
How could the post catalytic O2 sensor effect the fuel trim in some cars?

Please Log in or Create an account to join the conversation.

More
26 Dec 2019 16:10 #36120 by Desmond6004
Replied by Desmond6004 on topic Post catalytic O2 sensor
Someone will give a better answer but some vehicles will use the post catalytic sensor occasionally to adjust fuel trims when it sees readings that suggest that the cat can't handle the amount of fuel the normal trims is applying.

Getting involved in discussions because I have a lot to learn still.

Please Log in or Create an account to join the conversation.

  • Tutti57
  • Offline
  • Platinum Member
  • Platinum Member
  • Nissan Technician
More
15 Jan 2020 20:31 #36659 by Tutti57
Replied by Tutti57 on topic Post catalytic O2 sensor
I believe I remember Tyler doing some experiments with the rear o2 on a vehicle?



Nissan Technician

Nothing is ever as bad as it seems...

Please Log in or Create an account to join the conversation.

More
16 Jan 2020 13:38 #36667 by Andy.MacFadyen
Replied by Andy.MacFadyen on topic Post catalytic O2 sensor
ISTR Mazda use it on some models.

" Designed by clowns surpervised by monkeys. "


Please Log in or Create an account to join the conversation.

  • Tyler
  • Tyler's Avatar
  • Offline
  • Moderator
  • Moderator
  • Letting the magic smoke out since 2011
More
18 Jan 2020 11:30 #36711 by Tyler
Replied by Tyler on topic Post catalytic O2 sensor
The answer is, "It depends." :silly:

This thread may be worthwhile reading for you:

www.scannerdanner.com/forum/diagnostic-t...periments.html#26973

My general rule is, if the vehicle is equipped with an air/fuel ratio sensor, is has downstream fuel control. If it has an garden variety upstream O2 sensor, it may or may not have downstream fuel control.

How much control will depend on the specific year/make/model. For example, many Ford models I see have downstream fuel control, but it's very limited in its amount of control. 2% +/-, usually.
The following user(s) said Thank You: Noah

Please Log in or Create an account to join the conversation.

  • Not Allowed: to create new topic.
  • Not Allowed: to reply.
  • Not Allowed: to add attachements.
  • Not Allowed: to edit your message.
Time to create page: 0.280 seconds