Egr valve, carbon clean or replace?

[shandybet]

Hi all, had warning light for depollution system popping up on my grand c4, 1.6 hdi.
Took to the garage and he has put an addetive in the fuel and told me to blast it for a bit.

He said the other option is to take apart and clean but these engines are renowned for the parts breaking whilst doing so would be last resort as could end up just throwing money at it!

So I have tried blasting BUT every time I rev up above 2500rpm (ish) the car beeps and cuts out!

So, do I get a carbon clean done for approx £220 or just get him to open it up and hope it goes to plan?!

It’s a 57 plate
Vin VF7**************[VIN obfuscated, can be read by forum staff]
137000 miles

The handbrake warning light comes up also but that’s been an ongoing issue anyway.

I’m not mechanical at all if helps!!!

[H4wkeye]

If you had depollution system faulty message, it probably stored some errors. Did they read the errors via diagnostics? What did it say?

[shandybet]

These are the codes I read when having a look:

Car Scanner ELM OBD2
DTC report
Selected brand: Citroen

============1==============
P0402
Raw code: 0402
ECU: Engine control unit
Status: Confirmed
OBDII: Exhaust gas recirculation (EGR) system - excessive flow detected

============2==============
P1162
Raw code: 1162
ECU: Engine control unit
Status: Confirmed
OBDII: Fuel Temp. Sensor Circ. Short to Ground
Citroen: SIRIUS 81 - Exhaust gas recirculation. Coherence.

============3==============
P0193
Raw code: 0193
ECU: Engine control unit
Status: Confirmed
OBDII: Fuel rail pressure (FRP) sensor - high input

============4==============
P1586
Raw code: 1586
ECU: Engine control unit
Status: Confirmed
OBDII: Throttle Control Unit Throttle Position Malfunction
Citroen: Throttle control unit Throttle position malfunction

============5==============
P0087
Raw code: 0087
ECU: Engine control unit
Status: Confirmed
OBDII: Fuel rail/system pressure too low

============6==============
P1113
Raw code: 1113
ECU: Engine control unit
Status: Confirmed
OBDII: IAT Sensor Open/Short
Citroen: Intake air temperature (IAT) sensor circuit open/short

============7==============
P1351
Raw code: 1351
ECU: Engine control unit
Status: Confirmed
OBDII: Ignition Coil Control Circuit High Voltage
Citroen: IDM input circuit Malfunction/Ignition coil control circuit High voltage SID 803/EDC16C3 - Pre/Post heating relay circuit. Relay not controlled and glow plugs supplied.

============8==============
P0489
Raw code: 0489
ECU: Engine control unit
Status: Pending
OBDII: Exhaust gas recirculation (EGR) system - circuit low

============9==============
P0409
Raw code: 0409
ECU: Engine control unit
Status: Pending
OBDII: Exhaust gas recirculation (EGR) sensor A - circuit malfunction

[shandybet]

These are the codes I read when having a look:

Car Scanner ELM OBD2
DTC report
Selected brand: Citroen

============1==============
P0402
Raw code: 0402
ECU: Engine control unit
Status: Confirmed
OBDII: Exhaust gas recirculation (EGR) system - excessive flow detected

============2==============
P1162
Raw code: 1162
ECU: Engine control unit
Status: Confirmed
OBDII: Fuel Temp. Sensor Circ. Short to Ground
Citroen: SIRIUS 81 - Exhaust gas recirculation. Coherence.

============3==============
P0193
Raw code: 0193
ECU: Engine control unit
Status: Confirmed
OBDII: Fuel rail pressure (FRP) sensor - high input

============4==============
P1586
Raw code: 1586
ECU: Engine control unit
Status: Confirmed
OBDII: Throttle Control Unit Throttle Position Malfunction
Citroen: Throttle control unit Throttle position malfunction

============5==============
P0087
Raw code: 0087
ECU: Engine control unit
Status: Confirmed
OBDII: Fuel rail/system pressure too low

============6==============
P1113
Raw code: 1113
ECU: Engine control unit
Status: Confirmed
OBDII: IAT Sensor Open/Short
Citroen: Intake air temperature (IAT) sensor circuit open/short

============7==============
P1351
Raw code: 1351
ECU: Engine control unit
Status: Confirmed
OBDII: Ignition Coil Control Circuit High Voltage
Citroen: IDM input circuit Malfunction/Ignition coil control circuit High voltage SID 803/EDC16C3 - Pre/Post heating relay circuit. Relay not controlled and glow plugs supplied.

============8==============
P0489
Raw code: 0489
ECU: Engine control unit
Status: Pending
OBDII: Exhaust gas recirculation (EGR) system - circuit low

============9==============
P0409
Raw code: 0409
ECU: Engine control unit
Status: Pending
OBDII: Exhaust gas recirculation (EGR) sensor A - circuit malfunction

[GiveMeABreak]

The reason you can't blast the car (as any half decent mechanic would of told you) is because the engine management ECU is rev-limiting the engine for protection until the faults are resolved. So you need to get it into a decent garage and have these faults looked at by somebody with knowledge of these engines and fault finding expertise.

[H4wkeye]

The P1351 you can ignore for now, most HDIs seem to have it and it shouldn't cause issues. The EGR ones shouldn't put the car into safe mode from my experience/knowledge except maybe P0402. But for the other codes, you definitely need to go to some garage and have it all checked properly.