P0340 code
 

I finished putting back together my truck '03 ranger 4.0 sohc installed machined heads timed the camshafts using the timing tools. Got everything hooked back up but it will not stay running. Immediately is throwing the p0340 code camshafts position sensor a circuit bank 1 or single sensor. It actually shows it twice in my scanner. Please help, I'm at a loss and i hope it doesn't have to do with the timing...
edit: I installed new sensor and cleaned connections really good and it ran better for a little while but it is still giving me problems and still throwing the code.

P0340 Camshaft Position Sensor Circuit Malfunction
This is only 1 of the generic codes for cam sensor
P0340 Camshaft Position Sensor Circuit Malfunction
P0341 Camshaft Position Sensor Circuit Range/Performance
P0342 Camshaft Position Sensor Circuit Low Input
P0343 Camshaft Position Sensor Circuit High Input
P0344 Camshaft Position Sensor Circuit Intermittent

And it is a "circuit" code, which should mean one of the wires is disconnected or sensor is bad, or.............computer is bad
But it IS a generic code and not sure if 2003 computer had the P0000-P0099 codes yet or if your code reader can see those codes

Those lower codes have these
P0016 Crankshaft position/camshaft position, bank 1 sensor A -correlation Wiring, CKP sensor, CMP sensor, mechanical fault
P0017 Crankshaft position/camshaft position, bank 1 sensor B -correlation Wiring, CKP sensor, CMP sensor, mechanical fault
P0018 Crankshaft position/camshaft position, bank 2 sensor A -correlation Wiring, CKP sensor, CMP sensor, mechanical fault
P0019 Crankshaft position/camshaft position, bank 2 sensor B -correlation Wiring, CKP sensor, CMP sensor, mechanical fault

Which would come up if Crank Sensor and Cam sensor showed a mis-match in timing, i.e. a timing chain issue
But P0340 can have the same meaning, generic


While its a pain to do I would do compression test on all 6 cylinders to confirm cam/crank timing just to take that off the table
Cold engine
Remove all 6 spark plugs
Test each cylinder
Crank engine over with gas pedal pressed to the floor, this turns off fuel injectors and allows best air flow for compression test

WRITE it down
Move to next cylinder

4.0l SOHC runs 9.7:1 compression ratio, so 170psi is expected, but that really depends on the gauge and battery condition(cranking speed)
Point of compression test is the comparison of the PSI of all 6 cylinders

If compression is uniform across both banks and all cylinders , even if all are between 150-160psi its fine
Then you can surmise its an electrical issue

Valve cover off, nothing broken or anything as far as i can see. I just don't like how loose this chain is....

The cam sensor is on drivers side which is why the code, it out of time with crank sensor

Google: Ford 4.0L SOHC Front Timing Chain Replacement (Without Special Tools!)

Front chain should be tight fit without tensioner even tighter with it, maybe wrong chain or wrong guides?

I bought the truck with 22k miles on it so i don't think they had any engine work done. I don't know why it's so loose but I'm assuming it probably slipped.

It wouldn't be loose from slipping but being loose would cause lower compression from the delay in valves opening and closing out of time with the pistons

I don't see how the chain could get be stretched at 24k miles, maybe i need to manually prime the chain tensioner before i install it. I didn't do that, i just cranked it by hand and a little bit with the starter before running it.

After a closer look I see that the chain is not all the way around the lower sprocket.... Guess i have to take the front of the engine apart....

???

Well that is odd, that it didn't just come off, it is a tight fit behind crank/cam chains gear and should have made a racket, I would look at replacing both those lower gears

Update
 

So i guess when i was installing the heads the chain got enough slack in it to not be all the way around the lower sprocket, turning the engine over by hand caused it to come off further (that was the pop sound i heard) which messed up the timing. I had to pull the jackshaft sprocket to get the chain back on but i ended up replacing the chain sprockets and cassette just to be safe. The bad thing is that running it with that timing chain issue caused it to bent a valve so the left head is going to have to come back off....I think valve is bent because #4 cyl is showing 150 psi and all the others are about 200, and i get code p2197 O2 Sensor Signal Stuck Lean Bank 2 Sensor 1, plus it sounds like a diesel

Possible, the 4.0l SOHC is an interference engine, but just barely, but barely is enough

If you have a compressor and spark plug air adapter you can do a leak down on #5 and listen at tail pipe and throttle body for escaping air

I checked compressions on the right side again and now they are off, wtf? I thought the messing with the front timing chain and front of jackshaft wouldn't effect the timing of that side?
​​​​​

Finally got it timed right (both sides) and it seems to be running normal except now i have a rough spot when it's idling and it keeps throwing the p2197 code

Ford code P2197 O2 Bank 2 sensor 1 is 0 volts(stuck lean)
Bank 2 is Drivers side of a V6 and Sensor 1 is Upstream O2, closest to engine

Check to make sure O2 got plugged back in tight, or unplug it and plug it back in to clean connections
Check its wire, they can get melted by exhaust pipe/manifold

O2 sensors generate their own voltage using chemical reaction with Oxygen in the exhaust
0.1volt is high oxygen, lean
0.9volt is low oxygen, rich
Stuck lean can be 0.0volt

O2s have 4 wires, because they are heated, a 12volt wire and a ground wire for heater
And 2 wires for the sensor part
O2s must be heated above 600degF for the chemical reaction to work, which is why they are heated, gets them working fast after Cold Start

O2s do need to be changed every 12 years or 100k miles, only sensors that wear out on a schedule, they simply run out of the chemicals needed to detect oxygen, and of course the fail Lean, as voltage SLOWLY drops to 0.0volt, happens over years not days, or months, YEARS