I tried the method prescribed and is still running rough, do I need to take it out on the road? It is barely drivable.

 

The 85's were supposed to have the O2 sensor in the Y-pipe like that, but mine has it in the R-Exhaust manifold. Interesting, first 86' I have seen with the O2 in the Y.

Still should not mater much, leave it connected if you can, find another replacement, why not replace it with the same part if you think the Cat has failed?

 

Start it a few times, and take it for a 10 mile run....

 

No it should be running fine. Likely something else coincidentally failed.

You will need to pull the codes from the ECU. There are lots of posts on how to do it the search function will pull em up. I cheat and use a reader.

Ford Digital OBD1 Code Reader Scanner EEC-IV Lincoln Mercury Scan Diagnostic Too | eBay

 

Looks like a crimp connection on the O2 wire, that wire has about 0.5v on it.

If it is a crimp, I would remove the crimp and solder in a connector.

 

Who knows what the previous owner did as this is clearly not stock.

 

Yes it's crimped, I will solder it together if it'll help clear this mess I got myself into
QUOTE=vjsimone;17318756]Looks like a crimp connection on the O2 wire, that wire has about 0.5v on it.

If it is a crimp, I would remove the crimp and solder in a connector.[/QUOTE]

 

I would try and clear the ECU again and then take it out for a run.


I know the newer stuff has to re-learn to run right and based on what was posted it may be the same on the old stuff too?


In your picture it looks like you can cut the cat off right at the weld and still keep the O2 in place.
I would be temped to grind the weld down so I could pull the cat off and have more pipe to work with.
If you are just removing the cat make a "cat test pipe" to take it's place.
Dave ----

 

[/QUOTE]

Crimp connections under a vehicle don't last very long. This is a 0.0-1.0 v 02 device, single wire, using engine to computer ground. Won't take much corrosion on the crimp, or grounds to knock that voltage down in the lean range.

The tell tail, will be checking the codes, if you get a 41, the O2 connections will be suspect.

 

These older systems are not adaptive. There is nothing to learn.

 

Crimp connections under a vehicle don't last very long. This is a 0.0-1.0 vdc 02 device, single wire, using engine to computer ground. Won't take much corrosion on the crimp, or grounds to knock that voltage down in the lean range.

The tell tail, will be checking the codes, if you get a 41, the O2 connections will be suspect.[/QUOTE]

It's not a device electrical devices take the energy of electric current and transfor into some other forms of energy
It's a sensor, to specific it's a signal generator it generates a voltage that the ECU measure to ground.

Losing the O2 sensor would not make the truck run like crap it would present some mild driveability problems, it would run rich and blow black smoke and possibly have a hesitation but not run like crap.

And again the OP has not said exactly how the truck is behaving or exactly what running like crap means. It could be anything from vacuum leaks to bad ignition to valve train issues.

So best to quit taking shots in the dark till we have more information.

 

It's not a device electrical devices take the energy of electric current and transfor into some other forms of energy
It's a sensor, to specific it's a signal generator it generates a voltage that the ECU measure to ground.

Losing the O2 sensor would not make the truck run like crap it would present some mild driveability problems, it would run rich and blow black smoke and possibly have a hesitation but not run like crap.
It's barely starts and then needs to have slight gas pedal pressure to keep running. It chums, sputters a sounds like it's running on 4cy,l and all mistimed.
And again the OP has not said exactly how the truck is behaving or exactly what running like crap means. It could be anything from vacuum leaks to bad ignition to valve train issues.

So best to quit taking shots in the dark till we have more information.[/QUOTE]

 

For the older systems, true, 1978-1985

But for the 1986, F150, 5.0L, the Adaptive Strategy was added to the EEC-IV ECA, so not so true.

(The exception to the above, was that the mid-year 1985 F-150 had the 5.0L EFI as an option.

I happen to have one of these at my disposal, (Not by choice), I have had the privilege to cut my teeth, and other parts, on this beast for the past 3 years, with the help of the lads on this post and others. And still only understand 14% of what there is to know.)

Please read "Adaptive Strategy " below;

 

Agree, we always need more information.

A lot of us use these threads to brainstorm whilst we have the time, even though the OP has not responded, yet, to the last question, it is what it is, nothing to complain about.

There are always a dozen possibilities, or More for an OP’s issue, and with a 30 YO truck, it usually leans towards the More.

Not new to this crowd, when multiple components have failed over time undetected.

I see no “shots in the dark” displayed on these threads.