Notices
95.5-2004 Tacomas & 96-2002 4Runners 4th gen pickups and 3rd gen 4Runners

MPG Getting Worse!

Thread Tools
 
Search this Thread
 
Old 03-08-2006, 02:51 PM
  #21  
Registered User
 
4RUNN!N's Avatar
 
Join Date: Dec 2005
Location: San Jose, CA
Posts: 175
Likes: 0
Received 0 Likes on 0 Posts
Make sure you get an OEM o2 sensor.
Old 03-09-2006, 07:02 AM
  #22  
Contributing Member
 
X-AWDriver's Avatar
 
Join Date: Sep 2003
Location: Littleton,CO
Posts: 10,549
Likes: 0
Received 0 Likes on 0 Posts
I did a bit of highway driving up in the mountains and I'm sure the going down part really helps my mileage plus I haven't had to use 4wd in a while and I got 17.5mpg out of this last tank which is high for me.
Old 03-09-2006, 08:06 AM
  #23  
Registered User
Thread Starter
 
emptypockets's Avatar
 
Join Date: Aug 2005
Location: Spencer, Iowa
Posts: 887
Likes: 0
Received 0 Likes on 0 Posts
I'm going to take a closer look at things tonight. I got a new paper filter and am going to ditch the K&N, reclean the MAF and try to remove the o2 sensor. Anyone ever see one that was bad...what do I look for? I found replacements on Rockauto.com for between $80 and $250.
Old 03-09-2006, 08:22 AM
  #24  
Registered User
 
alotawatts's Avatar
 
Join Date: Jan 2006
Location: N.Seattle
Posts: 118
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by emptypockets
Anyone ever see one that was bad...what do I look for? I found replacements on Rockauto.com for between $80 and $250.
You can tell by looking if the sensor is clogged. Seafoam is advertised as O2 sensor safe. I have never heard of it fouling sensors. It's a good idea to check and clean the plugs but many will tell you thats not necessary either.
A new O2 sensor and valve adjustment made a big difference in milage with my Honda Civic.

Last edited by alotawatts; 03-09-2006 at 08:24 AM.
Old 03-09-2006, 11:06 AM
  #25  
Registered User
 
midiwall's Avatar
 
Join Date: Dec 2002
Location: Seattleish, WA
Posts: 9,048
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by emptypockets
Anyone ever see one that was bad...what do I look for?
It's hard to tell by looking at them and saying:"this is bad". Obviously, if the end is missing, or the case is cracked then that's bad, but since they spend their life in hot exhaust, they will discolor under normal conditions.

Here's a pic I found on the net claiming that these look "bad".
http://alflash.narod.ru/RX/Dsc01219.jpg

But actually, the only way to tell is to test them. Here're some words:
http://www.mr2.com/TEXT/O2_Sensor.html



I found replacements on Rockauto.com for between $80 and $250.
BE CAREFUL - don't be culled into buying a "generic" or "universal" sensor. Like was said above, buy only OEM and make sure you get the right one for your truck. Like I said above you have an A/FR sensor which will be about twice the cost of an O2 sensor.

RockAuto does look like they're selling it (Denso 234-9002) for $30 less than URD. Cool.
Old 03-09-2006, 11:53 AM
  #26  
Banned for stupidity
 
V_Runner's Avatar
 
Join Date: Feb 2006
Location: Ludlow, MA
Posts: 396
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by emptypockets
My 2002 3.4 MPG is slowly getting worse. About 6 months ago, it would do about 20 average of city and highway. That's down to about 15 now. I understand the cold plays some part in that, but not 5 mpg.

I've replaced the spark plugs, PCV valve, had the tires rotated and balanced and recently switched to 10w 30 Supertech Synthetic. About the only think I haven't done is the O2 sensor. Could that be the problem? Any ideas?
try seafoam...
Old 03-09-2006, 01:02 PM
  #27  
Registered User
Thread Starter
 
emptypockets's Avatar
 
Join Date: Aug 2005
Location: Spencer, Iowa
Posts: 887
Likes: 0
Received 0 Likes on 0 Posts
Um....yeah, already tried seafoam. I stopped by a local parts shop today and they said there's no way to clean the o2 sensor. They also said that there's no way seafoam can clog or ruin or clog the sensor. BS?
Old 03-09-2006, 01:03 PM
  #28  
Registered User
Thread Starter
 
emptypockets's Avatar
 
Join Date: Aug 2005
Location: Spencer, Iowa
Posts: 887
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by V_Runner
try seafoam...
Are you being sarcastic? LOL!
Old 03-09-2006, 01:21 PM
  #29  
Registered User
 
midiwall's Avatar
 
Join Date: Dec 2002
Location: Seattleish, WA
Posts: 9,048
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by emptypockets
Um....yeah, already tried seafoam. I stopped by a local parts shop today and they said there's no way to clean the o2 sensor. They also said that there's no way seafoam can clog or ruin or clog the sensor. BS?
BS to both.

A sensor _can_ get clogged/covered by oil spit that's a normal part of exhaust. If you look up how a sensor works, _all_ of the element that's in the middle needs to be able to react with the exhaust in order to get the most accurate reading. Cleaning that off could (not "will", "could") help. To clean that, soak it in brake cleaner - it's a great grease/grime remover.

And, since you've seen a Seafoam'd engine start after a couple of hours, think about all that stuff flying by the O2 sensor. It's inevitable that some will get on the sensor. See above for what to do about it.


Here's a bottom line... The idea of TRYING to clean the sensor is the difference between spending $3 on a can of brake cleaner versus $90 or $180 bucks on an O2 or A/FR sensor. You've got nothing to lose by trying to clean it. It won't restore the sensor to new (they degrade as a normal part of doing their job) but you may be able to stave off spending bigger bucks.


As a slighty beyatchy aside here... Given the days of time that we've been talking about the viability of cleaning it, you could have tried it already and possibly been back on the road smiling.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
primordialbeast117
86-95 Trucks & 4Runners
11
12-19-2015 12:23 PM
Davebarbier
86-95 Trucks & 4Runners
32
11-03-2015 03:28 PM
the_supernerd
86-95 Trucks & 4Runners
13
10-01-2015 09:20 PM
hiluxinargentina
86-95 Trucks & 4Runners
0
09-30-2015 11:12 PM
whiteyota93
86-95 Trucks & 4Runners
11
09-29-2015 02:31 PM



Quick Reply: MPG Getting Worse!



All times are GMT -8. The time now is 07:42 PM.