Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-16-2009, 01:27 PM   #11 (permalink)
Master EcoModder
 
Join Date: Feb 2009
Location: Phoenix
Posts: 595
Thanks: 106
Thanked 113 Times in 71 Posts
Replacing the o2 sensor just because the vehicle is reporting lean and subsequently enriching is silly, there are a dozen different problems that could cause this condition and just replacing the sensor that reports the condition is literally "shooting the messenger"

The post-cat o2 sensor really, genuinely, no-myth-about-it is not used for fuel trim. Period. In fact it CAN'T be used for fuel trim. Think about it: there's a frickin catalyst right before the sensor, how would the sensor know whether o2 readings are skewed by the effectivenes of the catalyst at that moment?

Replace your fuel filter first, it needs it anyway by 30k miles. See if that corrects the problem. Then use a fuel pressure gauge on the port that exists for that very reason to diagnose the problem rather than just randomly throwing expensive parts at the problem in hopes of accidentally curing it.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-18-2009, 11:00 AM   #12 (permalink)
Giant Moving Eco-Wall
 
DifferentPointofView's Avatar
 
Join Date: Dec 2007
Location: The Dale, IL (or A-Dale)
Posts: 1,120

The Jeep! - '95 Jeep Grand Cherokee ZJ Laredo
90 day: 23.75 mpg (US)

The Caliber - '07 Dodge Caliber R/T
90 day: 30.6 mpg (US)

The 'Scort - '98 Ford Escort LX
Thanks: 0
Thanked 7 Times in 6 Posts
Quote:
Originally Posted by shovel View Post
Replacing the o2 sensor just because the vehicle is reporting lean and subsequently enriching is silly, there are a dozen different problems that could cause this condition and just replacing the sensor that reports the condition is literally "shooting the messenger"

The post-cat o2 sensor really, genuinely, no-myth-about-it is not used for fuel trim. Period. In fact it CAN'T be used for fuel trim. Think about it: there's a frickin catalyst right before the sensor, how would the sensor know whether o2 readings are skewed by the effectivenes of the catalyst at that moment?

Replace your fuel filter first, it needs it anyway by 30k miles. See if that corrects the problem. Then use a fuel pressure gauge on the port that exists for that very reason to diagnose the problem rather than just randomly throwing expensive parts at the problem in hopes of accidentally curing it.
Expensive parts? my o2 was like 40 bucks.

I'm not talking about the post cat sensor. I'm talking about the pre cat sensor. And you don't have to replace it, you just do a test, and if it tests bad, you replace the sensor, if it tests good, then you look elsewhere.
__________________


Yea.. I drive a Jeep and I'm on a fuel economy site, but you just wouldn't understand... "It's a Jeep thing!" *Jeep Wave*

Did I Use Too Many Abbreviations? Here's The Abbreviations List
  Reply With Quote
Old 07-19-2009, 08:39 AM   #13 (permalink)
EcoModding Apprentice
 
Join Date: Jun 2009
Location: stl
Posts: 139

rusty - '00 ford mustang coupe
90 day: 24.31 mpg (US)

cbr929 - '00 honda cbr929 fast
90 day: 39.54 mpg (US)

Porshe - '06 Kawasaki zx10r
90 day: 47.21 mpg (US)

truck - '96 ford ranger
90 day: 26.51 mpg (US)
Thanks: 5
Thanked 11 Times in 8 Posts
check for vacuum leaks and evap system, either one will cause similar problems that you are seeing. One more thing, do you have an exhaust leak by any chance? that would do it too, even the smallest one.

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Keep A/C from running when you don't need it. TeamCF EcoModding Central 13 04-06-2009 12:55 PM
A Running Log website similar to EcoModder? 1337 Off-Topic Tech 2 03-12-2009 04:28 AM
Running on Air braddd Fossil Fuel Free 9 11-13-2008 11:48 PM
Just bought a '90 Metro XFi, have questions... ohmycivic EcoModding Central 29 10-13-2008 09:55 PM
Metro Running Light Mods!?!? bennelson EcoModding Central 7 08-14-2008 09:10 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com