oxygen sensor, trans troubles help!
Thread Starter
|
Junior User
Joined: Jun 2006
Posts: 66
Likes: 0
oxygen sensor, trans troubles help!
have a 1995 f-150 with the 5.0 in it. runs fine but every once in a while, the engine light will come on, and sometimes it will lose power, backfire, and cut out, then if i let up on the accellerator, it will run fine, and may or may not do it again. pulled codes, and got 172, oxygen sensor lean. cat is gutted, thus my problem. is there a way to fix this. i know without a cat a new sensor would not change anything. also the transmission seems to be taking off in second gear. if you manually shift it, 1st works fine, but when you pull up and stop, instead of downshifting to 1 it stays in second. unsure exactly what trans i have but trans code in door jam is "U". any thing i can do to remedy this problem?
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
172 is not an O2 sensor code and the EEC doesn't know if there is a cat is present so you can eliminate that from the list of potential causes. From the description of your trans behavior it sounds more like you have a VSS or TPS problem, were there any other codes?
Trans code "U" is the 4R70w.
Trans code "U" is the 4R70w.
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
172 is not an O2 sensor code and the EEC doesn't know if there is a cat is present so you can eliminate that from the list of potential causes. From the description of your trans behavior it sounds more like you have a VSS or TPS problem, were there any other codes?
Trans code "U" is the 4R70w.
Trans code "U" is the 4R70w.
Thread Starter
|
Junior User
Joined: Jun 2006
Posts: 66
Likes: 0
what is the HEGO code if not an oxygen sensor. manual defines HEGO as heated oxygen sensor or its circuit. the only other code was 225 which lists as knock sensor failure during dynamic response test. no other codes at all, and code reader was hooked up immediately after it was running this way. on the trans, is the 4r70w better than the e4od or worse? is there a way to check the tps and the vss to see if faulty?
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
Beats me. I was hoping for clarification too. 225's probably operator error (didn't hit the accelerator during WOT test). Here's the #'s you want to see for the TPS (which may still be in range so as not to through a code but also not completely accurate). As mentioned, that & VSS are the two big tranny disturbers, unless the tranny is disturbed itself! Ford Fuel Injection Throttle Position Sensor (TPS) With the tranny acting up, I'd consider tossin in a can of "Transtune". Can't hurt. When was the last service? Did it start actin up at the same time, or a separate issue?
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
on top of the diff. Couple of minutes.
Trending Topics
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
Yes exactly, it's telling you the engine is running lean and it(the EEC) wouldn't know that if the sensor was faulty. If the EEC reports both system lean(172) and system rich(173) codes at the same time or some other HEGO codes like 139/144(no switching) or 593(heater circuit failure) then it's a good possibility the sensor is the fault, but with just one code present there is most likely something else causing the condition.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
I'm leaning towards a problem w/ fuel delivery, lacking any other codes. No idle surging ? Check fuel pressure at rail. If asked specific questions, answering would help. You implied the tranny problem occurred simultaneously! It makes a difference as to addressing the symptoms.
Thread Starter
|
Junior User
Joined: Jun 2006
Posts: 66
Likes: 0
has some idle surging when idleing part of the time meaning it will surge for a few minutes, then level off and run perfect for a few, and then surge again. havent checked fuel pressure yet, but will do. also, as far as the trans goes, when taking off up a hill from a dead stop, the truck doesnt act like it has enough power to pull itself this could also be due to fuel delivery with the truck sloped downhill that much and not enough pressure to keep injectors working. out on the road level, it runs great, and while just idleing in park you can mash down pedal and go from idle to fast throttle, and it wont miss or cut out at all. i am like you, leaning more to fuel problem. has new tune up, and new fuel filter, can hear both fuel pumps hum when turning key on. also this might sound stupid, but got to thinking back tank gas cap is broken and just the part that screws in tank is there, could this have any effect?
Thread Starter
|
Junior User
Joined: Jun 2006
Posts: 66
Likes: 0
i usually run the front tank, and when it acts up and the ce light comes on, i have switched tanks to rear tank, and it will smooth out, light will go out, and it will run fine for a few miles, then light will come on again, it will backfire, and lose power again. i let up on accellerator, and it will pick back up and go on down the road, but the light will still be on. also the light is not on all the time, just when it starts acting up.
Der Postmeister
Joined: Sep 2006
Posts: 6,859
Likes: 560
From: Long Beach, Calimexiforia
i usually run the front tank, and when it acts up and the ce light comes on, i have switched tanks to rear tank, and it will smooth out, light will go out, and it will run fine for a few miles, then light will come on again, it will backfire, and lose power again. i let up on accellerator, and it will pick back up and go on down the road, but the light will still be on. also the light is not on all the time, just when it starts acting up.
Thread Starter
|
Junior User
Joined: Jun 2006
Posts: 66
Likes: 0
i put a new filter on it when i done the tune up. the old filter i took off seemed to be open also. i would lean toward the socks on the fuel pumps, but what is the chance of both being bad at same time. like i said, it runs fine down the road with what seems plenty of power. will cruise easily at 65 until the light comes on and then it acts up. also seems to do it more after it is warmed to operating temp.
Thread
Thread Starter
Forum
Replies
Last Post
jhfishdad
2007 - 2014 Expedition & Navigator
6
Jan 3, 2014 09:36 AM
