C4 Misfire and other faults

[Rickyhoppy]

Hi Everyone,
New to the forum and it's good to be here. Lots of great info and tales of woe. Looking for a little guidance on a fault that has presented itself on a recently purchased Citroen C4 1.8 petrol 2008, 109,000 miles on the clock. I bought this car as I have a lease car that has run out of miles sitting at 3 years old 10,000 a year and it's 31,000 due back in September.
Bought the car about 6 weeks ago the test drive was fine and no problems for about a week, then it developed a misfire Lexia states a permanent fault misfiring on cylinder No1 Permanent Fault Misfire on serveral cylinders generating a code of P0301. Changed the coil pack and plugs (gaps were huge) and performed a routine service and all was well for around a week then the car went into limp mode engine management light on, esp light, service light on, Faults were P0301 same as before, P1622 , P1336, P1671. Faults Log reads a 7157 external temperature fault D208 no communication with engine managment ECU and U1200 ESP fault. It seems to me to be overfueling the consumption is very poor when the fault occurs and all these light go on it struggles to climb hills even not so steep ones. I can send the screen shots from Lexia if required highlighting the data that was displayed when reading the fault codes. Anyone got any ideas I plan to change No1 injector tomorrow although I suspect that won't cure it. car always has a small misfire which does not generate a fault code until it goes into melt down with all the above mention lights on. Any help would be appreciated.

Many Thanks In Advance Ricky

[Lighty]

Tricky one, but the petrol C4's are very common for water temp faults, water switch itself fails & or water gets into wiring & causes high resistance, sometimes all the way back to,the ecu if unlucky.
It's worth checking live data to see if the figure of temp is stable & looks about right.
I have had a few that have read miles out & still don't log a fault.
We ususually cut a plug off an old loom & solder it to the car with a new top quality sensor.
May not be this, but worth a go.

[ekjdm14]

We ususually cut a plug off an old loom & solder it to the car with a new top quality sensor.
May not be this, but worth a go.

Is this cut/paste approach to break any possible capillary track from the sensor to the ECU? Also, I have heard of this capillary problem on a few PSA vehicles. Do you know if it's only petrol models or if it applies (presumably) to diesels too?

[Rickyhoppy]

Hi,
It is a strange one, I forgot to mention that when the fault occurs if you switch the engine off it will reset the fault and the engine management light usually stays on for a while, the fault may return with 10 minutes or it may not go into fault mode for a couple of days, the engine management light will usually go out after the engine is restarted a couple of times until the next time if goes into fault mode. I will check live data the next time it goes into fault mode as I have reset the fault codes and all seems ok for now

Many thanks for your reply Ricky

[Lighty]

We ususually cut a plug off an old loom & solder it to the car with a new top quality sensor.
May not be this, but worth a go.

Is this cut/paste approach to break any possible capillary track from the sensor to the ECU? Also, I have heard of this capillary problem on a few PSA vehicles. Do you know if it's only petrol models or if it applies (presumably) to diesels too?

The Diesel engine has a completely different coolant switch housing & doesn't really seem to suffer the issue as often, if at all.
I hadn't considered the soldering stopping the capillary process, but guess it prob would help.

[Justin657]

Did this fault ever get resolved please as got same issue at the moment on a 2006 c4 grand picasso with the 1700 petrol engine in