• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

O2 sensor Wrong?


holyford86

holyford86

Some guy with a problem
Supporting Member
Article Contributor
RBV's on Boost
GMRS Radio License
Joined
Aug 6, 2007
Messages
2,212
Reaction score
605
Points
113
Age
37
Location
Plattsburgh, NY
Vehicle Year
many
Make / Model
Ford
Engine Size
4.0
Transmission
Manual
2WD / 4WD
4WD
Total Lift
7
Tire Size
33x12.50R15
Seen this several times in rangers and explorers, every single one had been welded on the exhaust without the computer being disconnected, every single one got rid of these codes after a computer replacement. One of them was a 97 explorer with a 5.0 we pulled our hair out for days trying to figure it out. Ended up pulling the engine down to block, doing all related gaskets, testing (and replacing) all o2 sensors, and even testing the wiring harness between the computer and sensors. Replaced the computer with a good used unit and the problem immediately went away and hasn't been back. Another one in an 04 ranger with a 4.0, same issues, was purchased at auction and all o2 sensors and top end gaskets done, had custom welded on dual exhaust with the same codes as the ex. I'm not about throwing parts at issues but this is becoming a pattern for me.
 


Dads Toy

New Member
Joined
Jan 9, 2015
Messages
23
Reaction score
0
Points
0
Vehicle Year
1997
Make / Model
Ford
Transmission
Manual
holyford86 said:
Seen this several times in rangers and explorers, every single one had been welded on the exhaust without the computer being disconnected, every single one got rid of these codes after a computer replacement. One of them was a 97 explorer with a 5.0 we pulled our hair out for days trying to figure it out. Ended up pulling the engine down to block, doing all related gaskets, testing (and replacing) all o2 sensors, and even testing the wiring harness between the computer and sensors. Replaced the computer with a good used unit and the problem immediately went away and hasn't been back. Another one in an 04 ranger with a 4.0, same issues, was purchased at auction and all o2 sensors and top end gaskets done, had custom welded on dual exhaust with the same codes as the ex. I'm not about throwing parts at issues but this is becoming a pattern for me.
Click to expand...
That's good stuff to know. Well the blown fuse to the O2 heater circuit seem to be a big issue. I have been driving it now for about a week since replacing the fuse. Cold morning starts are much better. Don't get the O2 heater code no more. Just the lean code. Be working on that issue this weekend.
 

Dads Toy

New Member
Joined
Jan 9, 2015
Messages
23
Reaction score
0
Points
0
Vehicle Year
1997
Make / Model
Ford
Transmission
Manual
clean map sensor

I clean the MAP sensor today. Cleared the codes. So hope this works. Took it for a quick trip around the block. Seems to work ok. Will see how it works once I drive it more.
 

AllanD

TRS Technical Staff
TRS Technical Advisor
Joined
Jun 1, 2001
Messages
7,897
Reaction score
134
Points
63
Age
62
Location
East-Central Pennsylvania
Vehicle Year
1987... sorta
Make / Model
Ford
Engine Size
'93 4.0
Transmission
Manual
The "Downstream sensor" generally referenced as a "Catalyst monitor"
is actually a narrow band O2 sensor as it is dealing with gasses post catalyst
which are at least theoretically cleaner...

Mostly it is different because it is designed to do a different job.
 

Dads Toy

New Member
Joined
Jan 9, 2015
Messages
23
Reaction score
0
Points
0
Vehicle Year
1997
Make / Model
Ford
Transmission
Manual
Update

Will its been a couple of weeks now. Thought I would give a progress update. Might help someone some day. Truck is running good since replace the heater O2 fuse. Cold starts run fine. Still getting the too Lean bank code. I cleared it and work fine for about a day. Then it pop back up. I cleaned the MAF, intake tube etc. Thought that would have done it. Codes came back. So now I leaning on to the fuel system. Thinking replacing the fuel filter. Truck does run fine, has a little mis. Can't find any vacuum leaks.
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,363
Reaction score
8,369
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
After engine is warmed up, let it idle and unplug IAC Valve, this will cause it to close.
Idle should drop to around 500rpms or engine may even stall, either is fine, it means no vacuum leak.
If idle stays up then there is some air leaking in from somewhere, try testing for leaks at this time, when idle drops you found the leak.


Fuel pressure test might tell you something, if pressure is lower than computer expects then it has to open injectors longer, so will set a lean code because fuel trim is high.
 
You must log in or register to reply here.

Sponsored Ad


Sponsored Ad

Staff online

Members online

Total: 519 (members: 18, guests: 501)

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Truck of The Month


Shran
April Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

Latest Album Photos

Hunters
20240409_190831.jpg
20240409_190818.jpg
20240409_180824.jpg
20240409_182648.jpg
20240409_181010.jpg
20240408_175026.jpg
99 Ranger
20200706_161414.jpg
20240207_155117.jpg
20240207_155111.jpg
20240207_154537 - Copy.jpg

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top