P1338 Engine Light/Intermittent misfire

Hi,
Looking for ideas/help/advice please with a 2014 C3 1.0 68bhp 3cylinder, EBO engine.Total mileage 46,000 miles.
The car has been in the family for the last 3years covering 20,000+miles without any issues at all.

A few weeks ago after approx 1mile from home, engine cold, the engine management light came on and the car ran very rough. The OBD11 reader shows P1338 intermittent misfire on No2 cylinder.

If the light ( P1338) is erased the car then runs just perfectly as before. This has now happened a total of three times over 3weeks all after first start and with 1 mile from home. It seems as if it only happens when the car has recently been started from cold. The rest of the time the car runs perfectly and has covered probably 50-60 miles between each occurence.
I have changed No2 coil pack and spark plug. The car has now just done it again, management light comes on, P1338 intermittent misfire on No2 cylinder. Until the light( P1338) is erased the engine runs very rough. Light erased and the engine runs perfectly.

Any help, thoughts, theories or ideas would be much appreciated.

shoestring wrote: ↑Sun Nov 07, 2021 1:52 pm
I have changed No2 coil pack and spark plug. The car has now just done it again, management light comes on, P1338 intermittent misfire on No2 cylinder. Until the light( P1338) is erased the engine runs very rough. Light erased and the engine runs perfectly.

Any help, thoughts, theories or ideas would be much appreciated.

It is worth checking to compare all the spark plugs with each other.

I was going to suggest that 'are looking at the correct plug, and not counting from the wrong end' , but with only 3 cylinders, I don't think it would be possible to get no.2 plug wrong


You can also swap parts between cylinders rather than replace to see if the fault moves (similar, but different P code). This would prove the part faulty.

You could try swapping the injectors over, as you have done the other parts already.

Yes the problem must be related to No2. As you say there are only 3 cylinders and No2 is the middle one so don't think I have that wrong. The OBD11 reader specifically says 'P1338 No 2 Cylinder intermittent misfire'.
I have been reading about Cam or Crank sensor on other make forums and they say that can throw up P1338 . However I wouldn't have thought that would affect a specific cylinder ....Any thoughts?

Yes it is an idea about swapping injectors around, but slightly concerned about the injector seals if I do that.
What I don't understand is that after just erasing P1338, without doing anything else, the car runs just perfectly and continues to run fine until the next time.
One though though it doesn't run rough and then the EML comes on, it only runs rough after the EML has come on...that is another thing that I find puzzling.
It also appears to only do it from cold after a short distance( 1mile). But 3 times in about 3weeks only after doing loads of longer runs in the meantime!

Thanks.

shoestring wrote: ↑Sun Nov 07, 2021 6:08 pm I have been reading about Cam or Crank sensor on other make forums and they say that can throw up P1338 . However I wouldn't have thought that would affect a specific cylinder ....Any thoughts?

I don't know if the 3 cylinder has a crank sensor, on some previous PSA engines the crank signal was taken from an injector and the crank senor was never fitted.

shoestring wrote: ↑Sun Nov 07, 2021 6:08 pm Yes it is an idea about swapping injectors around, but slightly concerned about the injector seals if I do that.

Be careful and you may find the injectors seals need replacing, if not, they should be good to re-use. Maybe get a few before hand, just in case?

shoestring wrote: ↑Sun Nov 07, 2021 6:08 pm What I don't understand is that after just erasing P1338, without doing anything else, the car runs just perfectly and continues to run fine until the next time.

ECU has detected a fault and set the car in to limp home or a reduced capability mode (less power). This is to protect the engine.
When you clear the code, the limit is removed and is only set again when the fault is detected again.

To resurrect this thread
The saga of my C3.1 0 vtr EBO engine continues ..still getting P1338 intermittenly coming on...mileage varies between EML events but usually every 100 or so miles. Car runs very rough EML comes on. Car undriveable. Error code P1338- Says Intermittent misfire on No2 cylinder combustion misfire. ( Impact on Catalytic Converter)
Items changed so far:-
No 2 cyl Coil Pack
No2 Spark Plug
No2 Fuel Injector.

Now at a loss on what to do...In between EML coming on, which can be weeks in between, the car runs absolutely perfectly without any problems at all.
The only thing I have noticed though is that when this EML light event happens the engine fan cuts in...But the car is definitely not overheating, but is this because it is running rough?
Any ideas on what I change next...Thought currently are to maybe to change Coolant temp sensor? Or maybe Lambda sensor...
All ideas would be very much appreciated!

shoestring wrote: ↑Sun Nov 07, 2021 6:08 pm
I have been reading about Cam or Crank sensor on other make forums and they say that can throw up P1338 . However I wouldn't have thought that would affect a specific cylinder ....Any thoughts?

I am NOT familiar with this engine so take what I say with a grain of salt.

The OBD2 protocol is very sketchy. Apart from a few core DTCs the codes are wide open for interpretation. LEXIA and Peugeot Planet are programed to "interpret" the DTC and tell you what the ECU is reporting. Depending on the engine that could be 1 of a couple of responses. It all depends what PP or LEXIA has been "told" to say. It's the same for generic OBD2 scanners, they just tell you what they are "told" to say. Some OBD2 scanners ask you about your car or engine to better tailor the answers.

It seems that (on the surface) your problem is not on cylinder 2, as you have replaced most of the components associated with cylinder 2. Now, there are a few other things associated with cylinder 2 that it could be (carbon build up on one of the valve seats, lack of compression, for example) but you really don't want to go there. These other faults involve a major tear down of the engine!

Classic "misfires" usually throw up a 'temporary' code and usually don't cause the engine to go into limp mode. You can usually feel the car hesitate but the engine tends to keep going. HOWEVER, camshaft position faults DO. An alignment issue between the pistons and the valves could be catastrophic so the engine ECU errs on the side of caution and tends to go into limp mode.

P1338, as you said, is also associated with a cam shaft position error. You can address that without too much trouble.
Are you using the correct weight and type of oil? Oil getting old? The variable valve systems in engines these days are very reliant on the oil for correct operation. The engine ECUs are becoming very finicky. Very small deviations from nominal will cause them to complain!
You could try swapping the camshaft phaser modulating valves (if they are the same). See if the code changes.

Sorry, I'm not familiar with this engine so I cant tell you specific things to try.

Thanks for the reply and thoughts. As you may have gathered in my latest post I am now getting rather frustrated with this car!
This morning I have changed the Oxygen Lambda Sensor ( the one before the Cat)in the vain hope that may do something but I am not hopeful and I can't keep throwing money at it!
You mentioned oil....Using Total 9000 as recommended by Citroen which is changed religiously every 6000 miles and has done 4000 miles since last change so I can't think that has any bearing on the problem. It uses next next to nothing between changes.
I will try it again but with not doing many miles with it but it may take a few weeks/100-200miles to know if I have made any progress.
Thanks again for the input..Keep the ideas coming please.

Well,.. today a slight development!
As I said previously on Saturday I changed the preCat Lamda sensor and over the weekend the car did approximatly 30miles all running perfectly with no EML shown.
This morning on startup the car briefly ran rough and EML came on ...After turning off the engine and restarting the engine then ran smoothly with no EML showing at all.
Plugging in the OBD11 reader shows a different error code from that shown previously . Todays error code is P1336!....and not P1338 No2 cylinder that was shown previously.
So...the question is what do I now change?
Changing the preCat Lamda sensor two days ago appears to maybe have changed things! Am i now on the right track ?....There is also an afterCat Lambda sensor fitted so does anyone have any thoughts on if I should now change that?

On searching other forums though opinions differ and P1336 tends to infer either Cam or Crank angle sensor?
Unsure if I can continue with this car...just losing the will to live over this problem with seemingly no clear answer.

Unfortunately these are generic codes and could be either the crank shaft or cam shaft sensor.
The P1336 seems to indicate a bad sensor or an associated wiring issue. I guess you can only check both sensors? My guess is a sensor is heating up and going open circuit for a second or two and then functioning normally. However once the fault is logged the engine goes into limp mode. Again I am not familiar with this engine but I would have said the engine would be "throttled back" in limp mode, not run rough. I don't know.
I would check the connector at the sensors for an anomaly (corrosion) and check the wiring loom from the connectors back to the engine ECU and check the plugs at the engine ECU.
Remove the sensors and inspect them, particularly the end that senses the camshaft/crank shaft position. Make sure the electrical connectors and sensors are secure.
I guess the next step would be to replace the sensor but which one? You need to get a LEXIA onto your car to pin down the problem.

Again I don't know much about these engines and I don't know if there is one or two camshaft sensors? Sorry.

Hmm just thought. Usually the loss of the crank shaft sensor shuts the engine down. Without the crankshaft sensor the engine has no idea where the timing is. I guess it could derive the timing from the camshaft sensor? Sorry but that doesn't really help you.

If I was to make a wild guess I would go for the camshaft position sensor. It would sit in the top of the engine where it is very hot. If there are two...well...I don't know what you would do then.

Thanks once again for your thoughts..much appreciated. When one is trying to think through these things it does help to have another train of thought!
I too have been thinking that the Camshaft sensor is the next thing to try.
I will see what the damn thing throws up this week!!

Thanks,