02 Sensor Question.
Thread Starter
|
New User
Joined: May 2018
Posts: 6
Likes: 0
02 Sensor Question.
i have a 2005 F150 with the 5.4L.. the previous owner removed the cats and straight piped it when the cat clogged. so now i just have my upstream 02 sensors. so of course i have check engine light for 02 sensor heater circuit sensor 2.. my question is i also have bank 1 lean and bank 2 lean.would not having the downstream sensors cause the computer to think its running lean? im getting 11mpg in town or so. It doesnt feel like loss of power and runs fairly well. just curious if not having downstreams trick the computer to think its running lean when its not?
Logistics Pro
Joined: Jan 2001
Posts: 3,740
Likes: 37
From: Central NYS
i have a 2005 F150 with the 5.4L.. the previous owner removed the cats and straight piped it when the cat clogged. so now i just have my upstream 02 sensors. so of course i have check engine light for 02 sensor heater circuit sensor 2.. my question is i also have bank 1 lean and bank 2 lean.would not having the downstream sensors cause the computer to think its running lean? im getting 11mpg in town or so. It doesnt feel like loss of power and runs fairly well. just curious if not having downstreams trick the computer to think its running lean when its not?
The upstream O2s are used for fuel control and if the PCM adds max fuel to try and get the mixture back to stoic, it sets the lean code(s).
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
What is the exact code number you are seeing? Given your fuel milage I wonder if the code is actually (at lean adaptive limit) which means the computer knows the engine is running rich but has reached it's adjustment limit in it's efforts to lean it out. If that is the case you may have a problem with the fuel delivery system, fuel pressure too high or maybe one or more injectors are dirty and leaking extra fuel into the motor. Either way it's not likely you have a primary O2 sensor problem.
FYI, there are O2 eliminators available for the downstream sensors that will "fix" you check engine light problem.
FYI, there are O2 eliminators available for the downstream sensors that will "fix" you check engine light problem.
Posting Guru
Joined: Jan 2015
Posts: 1,083
Likes: 33
From: San Antonio, Texas
What is the exact code number you are seeing? Given your fuel milage I wonder if the code is actually (at lean adaptive limit) which means the computer knows the engine is running rich but has reached it's adjustment limit in it's efforts to lean it out. If that is the case you may have a problem with the fuel delivery system, fuel pressure too high or maybe one or more injectors are dirty and leaking extra fuel into the motor. Either way it's not likely you have a primary O2 sensor problem.
FYI, there are O2 eliminators available for the downstream sensors that will "fix" you check engine light problem.
FYI, there are O2 eliminators available for the downstream sensors that will "fix" you check engine light problem.
Trending Topics
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
You will kindly notice my original response was before the actual code numbers were known so it was a shot in the dark.
Hotshot
Joined: Jan 2004
Posts: 19,765
Likes: 1,082
From: St Louis
I find that statement a bit surprising so I had a look on the web for these and all I see are things that look like 1" sensor spacers, harness extensions of some type and other crap, it seems this market has been totally saturated with gimics of late. I had to dig to find the device I was referring to which is something that plugs into the chassis wiring harness only to simulate the output of an O2 and the sensor itself is totally removed. I don't know where one would buy these but when you do it will look like this. These will address your missing downstream sensor codes only, they won't do anything for the lean codes which I agree are most likely the result of a vacuum or exhaust system leak.
In order for such a device to emulate completely missing downstream O2 sensors on this era of Fords, it would have to do two (at a minimum) specific things:
1. Successfully emulate the heater circuit. This could be done with a suitable high wattage, low value resistor.
2. Pass the PCM's test of the sensor's switching capability prior to running the catalyst efficiency test. This would fail since the simulator has no way of knowing when that test is executing.
Knowing how something is supposed to work is key to understanding whether or not an add-on is likely to work.
Posting Guru
Joined: Jan 2015
Posts: 1,083
Likes: 33
From: San Antonio, Texas
i have a 2005 F150 with the 5.4L.. the previous owner removed the cats and straight piped it when the cat clogged. so now i just have my upstream 02 sensors. so of course i have check engine light for 02 sensor heater circuit sensor 2.. my question isi also have bank 1 lean and bank 2 lean.would not having the downstream sensors cause the computer to think its running lean? im getting 11mpg in town or so. It doesnt feel like loss of power and runs fairly well. just curious if not having downstreams trick the computer to think its running lean when its not?
Thread
Thread Starter
Forum
Replies
Last Post
baddad457
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
6
Aug 13, 2017 07:33 PM
Nothing Special
1987 - 1996 F150 & Larger F-Series Trucks
5
Nov 16, 2016 05:54 PM
BrassMonkey
1997 - 2003 F150
5
Nov 21, 2013 11:01 AM