Ford O2 Diagnosis on my F150,Explorer and Lincoln,

C

cobra98lsc

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FrankieX or anyone else if you can give me a small bit of advice on these 2 issues would be greatly appreciated.
I am having some crappy luck on 2 other Fords this wkend, i had codes in my 99 F150 4.2 4x4 for an 02 sensor Heater Circuit Malfunction, so i checked wiring and replaced the 02 with a Bosch factory unit.
Still same damned code, cleared PCM etc.
Then on my brothers 96 Explorer i have a 02 Sensor Circuit slow to respond on Bank 2 Sensor 1
Pop in a new 02 on both sides since 106k miles, now i get rewarded with 3 codes, P0135, P0153,P1131 First code blew me away since now on BANK 1 Sensor 1 when for months all i had was the Bank 2 slow to respond DTC. Now i have a heater malfuction, and Insufficient Control Vavle Sensor/Lean? WTF is going on with these 02 sensors.

If anyone can help i really appreciate it as i am fixing these 2 cars for family so i can get the $$ to fix my Mark, Thanks in advance.

Are the Bosch 02 sensors from Zone or Oreily any good? i have never had so much trouble in my life with simple 02 repairs.
 
RE: Ford O2 Diagnosis on my F150,Explorer and Lincoln,

There's nothing quite as never-ending as fixing cars for family. I avoid it whenever possible!

Obviously most of my experience is with Ford replacement O2s, and they're pretty reliable. I know this is going to sound like a sales pitch, but it's true: over the years, I've used aftermarket O2s because of price considerations a number of times. Every time I have, it's been a disaster. It has ended up costing twice as much because I've had to get the no-names out and put Fords in before the problems were solved.

I need more info on the F150. What codes exactly?

The Explorer:
P0135 = heater circuit open, O2 # 1-1. That's passenger side, front.
I know how difficult those connectors are to unclip, so most of them have been broken out of their brackets over the years. This leads to an interesting problem. On Ranger/Explorers, the "Y" formed by the harness down the back of the engine is very easy to flip if both sensor connectors were undone at the same time who-knows-when. You cannot take for granted that the engine harness connector hanging behind the passenger head is actually for #1-1. Look at the wiring; you're going to need to for diagnosis.
There's 4 wires to all your O2s, but here's #1-1:
Solid Orange and Grey /Light Blue stripe are the sensing wires. Be sure they're the right colours, but don't touch them.
Light Blue/Orange stripe- this is the 12v power (key on) for the heater. With the connector unplugged, is there power on the harness side?
Red/White stripe- ground provided by the PCM. Use a test light reversed (alligator clip on positive) on the harness side and see if it lights. Try this within 5 min of turning the key on. After that, the PCM may turn the ground off.
If you've got power and ground, the heater in the new O2 is NFG. If not you'll have to trace wires. It cannot be a fuse. ALL O2 heaters are on the same circuit. If the fuse blows, you'll get ALL O2 heater circuit codes.

P0153 = slow switching response, O2 # 2-1 (driver's side front)
Very rarely can slow switching be caused by anything other than a defect in an O2's internal sensing tip, which is actually a small chemical generator.
A few other possibilities: a SEVERE exhaust manifold leak, allowing fresh air to enter the manifold before the O2, or an ignition miss SO BAD the sensor is being washed with raw fuel.

P1131 = fuel trim correcting rich for a perceived lean condition, Bank # 1.
I think we already discussed this to death regarding your MarkVIII. Everything there applies here, but the fact that the PCM only seems to think one side is lean makes me more inclined to suspect a vacuum leak.
'90s 4.0L Ranger/Explorers were NOTORIOUS for leaks from the O-rings between the upper and lower intakes and the O-rings around the EGR tubes where they enter the upper manifolds. They would trigger the lights when everything was cold and contracted. If I let the engines warm up, the manifolds would expand, the leaks would close up, I'd clear the codes and lights, and everything would be good until the next cold start.

Here's the next thing I want you to do: don't just clear the codes. Disconnect the battery for 5 min., which will clear all adaptive learning (such as fuel trim correction) and run the Explorer until the MIL/"Check Engine" light comes back on. See what codes return. If that fancy new scanner of yours is capable of Freeze Frame, you'll be able to see what was going on when the PCM made the decision to turn the MIL on. If ECT was at a low temperature, you can be pretty sure about the cold intake leak.

Good Luck!
 
RE: Ford O2 Diagnosis on my F150,Explorer and Lincoln,

First i want to say thank you very much for sharing your knowledge and expertise here.

Funny thing is i didnt read your response until after working on the explorer again last night. I notice a bunch of oil sweat all around the back of the intake where the upper and lower come togeather, appears to be leaking to me, so i tightened up the nuts on the studs that hold that togeather. THen i read your response about the o-rings, and sure enough it ran great hot without codes, then got home cooled down fired it back up and MIL!

On the Explorer the Bosch O2's i got from Autozone are the same exact brand as the ones that i pulled out, they had both the BOSCH and the FORD oval stamped in them and appeared IDENTICAL. On the 99 F150 they looked nothing alike. The factory sensor was obviously bad.

I cleaned connections and all wiring is in tact and still attached to the harnesses nice and clean.

Freeze Data shows P0133 @1520RPM ECT is 190 (orginal code)still doing it.

P0135
P1131

The 2 above codes 2 did not start until after i installed the new sensors.
Is bank 1 sensor 1 the driver side right?
The passenger side is a @)#$()@#* to get to the connector above the transmission etc.. whoever thought of putting that sensor connector up there needs a date with a baseball bat.
 
RE: Ford O2 Diagnosis on my F150,Explorer and Lincoln,

Isn't it!?! Imagine doing that on an Exploder that just came off the highway and the customer wants to wait? Our common comment is, "Just get me the name and address of the guy who thunk this up!"

If you find cylinder #1, you've found bank 1 (except in our Mazda products). That makes bank 1 passenger side.

P0133 - Now you've got slow switching on bank 1!

Look at your harness and connectors very carefully. Are the connectors still in their clips? Does the harness down the back of the engine look out of place? Think this through... if the harness connector is plugged into bank 1 side O2, the PCM will be trimming the opposite bank and looking at the wrong O2 sensor voltages for trim feedback. WEIRD things will happen!

Be sure to check for corrosion or broken pins, also.

I gave you wire colours for the #1 connector. Here's #2:
Solid Orange and Red/Black stripe = sensing circuits
Blue/Orange stripe = Heater power
Yellow/Blue stripe = Heater ground.

I still wouldn't rule out the vacuum leak. Once the O-rings are squashed, tightening doesn't help much.

Keep going! We'll get this solved.
 
RE: Ford O2 Diagnosis on my F150,Explorer and Lincoln,

Well i fixed the Explorer.

Intake gaskets were gone.

1 02 was not plugged in all the way but i swapped them for Ford units anyhow.. runs like a top.

ON the F150 i still have the 02 Heater code on bank 2 sensor 1
I replaced the sensor and the stupid thing does the same thing.
I did check the wiring with the VOM and i have 12v on the heater lead. and the ground does turn on and off with the PCM/ign switch.
So like you said if one works the other should work.
Next thing i am going to try is changing out the BANK 1 sensor maybe the wiring is backwards from ford even though its all factory and in tact and looks to have never been touched.
Besides there is NO WAY the passenger side harness could ever reach the other side.

Maybe new heater is NFG just like you stated above.

Anyhow thanks a zillion for the help.

BTW I parked the Lincoln and purchased a 2000 Grand Cherokee Laredo in great shape.
 
RE: Ford O2 Diagnosis on my F150,Explorer and Lincoln,

An Exploder with a leaking intake?? Surprise, surprise.

The problem with the reversed wiring can only ever happen on 3.0L Rangers and 4.0L Ranger/Explorers. No other vehicle's harness is configured like that.

I'm just repeating myself: bank 2 sensor 1 is driver's side front.
Heater power = Red/Yellow stripe (live with key on)
Heater ground = Yellow/blue stripe (switched by PCM)

I'm glad you got the Exploder sorted out. The F150 should be easier.
 
RE: Ford O2 Diagnosis on my F150,Explorer and Lincoln,

I must be completely stupid.

I have been thinking bank 2 is the passeneger side!!

Dammit..

Ok that explains why i havent fixed the F150 i only changed the passenger side # 1 sensor.

Thanks again i will re check it in a week or 2

I am rebuilding the top end on a 71 442 Convertible so my garage is in-use at the moment.
350 Rocket motor, porting out heads and 3 angle, new cam,lifters,Barry Grant carb,intake,ceramic headers,Accel dist, etc.
:)

Thanks again your help is greatly appreciated.
 
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