Greetings I'm helping a buddy but I'm more of a diesel mechanic that remembers gas engines. I do have a decent scanner.

Truck is 1998 f150 4x4 4.6l True hack dual exhaust.
Truck lost power, runs like a bad miss or 2, and smokes white from bank 2.

Temp reads open circuit and 118 code.
Freeze frame data shows
Fuel system bank 1 "open loop"
Bank 2 "not reported"
Fuel trim bank 1 and bank 2 both at 21.84% This was 907RPM.

I crawled under to find only 3 oxygen sensors. 1 upstream and 2 downstream.

Total of codes:
118 coolant sensor circuit high input.
1000 OBD 2 readiness
117 coolant sensor intermittent
500 vehicle speed sensor
1352 ignition key circuit fault.

It feels just like an old v8 with two spark plug wires mixed up the way it shakes.
Idle bounces 600 to about 1400 on start and eventually finds rough steady idle around 900.

Do these normally only have 1 upstream and 2 downstream 02 sensors?
No misfire codes?
He changed spark plugs which were rich fouled.

Where to start without codes. I thought these were somewhat smart at detecting a miss.

I have read of a few somewhat normal problems like , wires shorting, intake vacuum leak coolant or oil into plug hole, coil packs, etc.

What should I monitor on scanner for hopefully detecting?

Temp sensor won't throw off fueling really bad right?

What should manifold vacuum read approximately at 900?
I didn't have tools or spray when I saw the truck.

I can't throw parts at it being in Panama so would rather test and order. They stock nothing here.

 

I had an Explorer that had a temp sensor go WAY OUT and was reporting over heating... That made the computer retard the timing to try to cool down the motor ( which was not actually hot)........ It got to the point that with the retarded timing, the motor would not restart when warm... and finally would not start at all............. maybe not your problem, but I would address the CODES first.

 

Thanks for that. It is on the order list but I also have not yet confirmed the wiring. Because they won't have that sensor here I'll measure the resistance on a known good one from a mustang I have to compare and try a resistor temporarily.

Because it's dual exhaust and only white smoking one side I believe there is more problems.

How many 02 sensors are there stock? Anyone? This has 1 upstream and 2 downstream.
Plus the scanner saying bank 2 not reported seems odd to me unless it defaults that way when warm or cold or something weird. So much I don't know about non diesel fuel injection. lol

 

Your report clearly describes the causes of the issues.
Codes 117, 118 are open cylinder head temperature circuit.
It has consequences.
The computer looks at it as a very cold conditions and shifts the fuel tables + RICH..... First problem.
.
Code 1352 is the primary circuit from the PCM coil driver to the coil of cylinder 2.
Nothing to do with the ignition key circuit. Second problem.
.
Code 500 is the VSS circuit or the sensor.
It has an effect on the speedometer and transmission shifting. Third problem.
.
There should be two Ox Sensors, one for each bank.
If the exhaust and wiring has been hacked, that's why your missing one.
They are both in the head pipes close to the exhaust manifold outlets. Forth problem.
.
Do the repairs and restore the OX sensor and all codes will clear providing there are no other faults.
The codes 1000 is not really a trouble code and will clear when all PID tests pass.
.
Your Scanner told you all the faults. It's a matter of interpretations of the data. You must use Ford descriptions, not those of the Scanner. Only the codes.
Good luck.

 

Thank you very much sir! Because were remote I'm planning on ordering intake gasket, wires, the 2 quad coil packs (per recommendation if you agree) Are the MSD or ACCEL ones better I just saw they are cheap and summit doesn't carry motorcraft.?, And O2 sensor, temp sensor, and speed sensor once identified.

I'm starting the search now but doesn't this truck have 1 temp sensor in the head? I need to search it's location. You seem to say it's not the intake manifold sensor but the cylinder head sensor?

I'm going to ignore my head scratching that the left exhaust is the white smoking one and the code being for number 2.
Thanks again. Great info and He and I appreciate it.

 

The CHT is on the driver side head in the center 'under' the intake manifold.
Both codes suggest the circuit is going open and shorted.
Check the harness first.
The white exhaust is coolant vapor not smoke.
Steam is present during cold starts until the cats heat up, then it largely disappears quickly after leaving the tail pipe.
This can be anything from a head gasket to a crack in the head or block.
It can contaminate the OX sensors and damage the cats from the Glycerin content as well as causing that cylinder to misfire
Sort the issues out one at a time.
Start with the coolant issue first to see if it's worth the other parts, access and time..
After the motor is running smooth, look at the cats for activity by watching their Ox Sensor switching indicating their relative health.
You have a nice repair project going.
Good luck

 

Look at the coil plugups for seating, wire issue etc.
The Ox Sensors while the same sensor front and rear do two different things.
The fronts control fuel injection with their signal back to the PCM.
The rear sensors monitor the Ox level storage in the rear cats.
This is a measure of Cat health.
It is done by the PCM monitoring their switch 'ratios' between the front and rears sensors.
In a satisfactory cat assembly the rear sensors do not switch very far from their relative fixed outputs.
It's when they begin to follow the front sensors switching that trouble is beginning to develop.
Gas engines have a lot more overall complexity than Diesels.
You need to lean how the systems work to be able to sort out the issues.
Good luck.

 

Sorry I screwed the pooch big time on description.
It is a hacked exhaust.
There is NO cats.
There is an O2 sensor at the end of the drivers right manifold. Then there is an O2 sensor on each side about a foot and a half down stream. No cats in between.

From my limited reading in the past that doesn't work unless you somehow mask the reading from the ECM/PCM to furnish a number it's happy with.

Thanks in advance for the help.

At the same time don't underestimate the complexity of new common rail diesels. We can't program for X air fuel. On many programs we program X pressure at X psi for X load and work through trial and error and countless hours on a track or load cell dyno. Averaging 200 or 300 cells to program for one table, LOL It's just very different. Old 6BT Cummins ? Sure. Rank up the pressure and advance the injection timing a few degrees But honestly still not that simple.

I loved old carbureted gas engines. I seriously respect newer ones but have yet to work on many other than some basic stuff. My POS mustang said I had a cam position sensor problem. 2 minutes on the internet and found out it was an alternator AC noise problem. Some Cummins had similar problem also.

 

Well you cannot restore this truck to good running order unless you put stock parts back on as factory.
The front sensors cannot be tricked because they provide signal to control fuel injection. The front sensors need to be close to the exhaust outlets because there is loop timing involved.
If located to far down stream, they run too cool and slow to respond at slower engine speeds.
Without them the program goes to it's fixed rich fuel tables to run the motor same as open loop.
Result is poor fuel mileage, poor cold starts etc.
What are you going to do? Fix it or junk it!.
You need at least $600 worth of after market cats assemblies to start with to get the pipes that are needed back to a muffler..
Plus all other issue there are to repair.
There is an old saying that says when something is free it's not really free if you have to put all that work and expense into it.
Good luck.