2009 C5 depollution fault

[elcustardo]

Having had a few Citroens over the years. not an error message I'm unfamiliar with.

2009 1.8 petrol

So the car has intermittently been a little hesitant at low speeds over the last few weeks.
Today it upped ante after work. no power/response from the accelerator. Had to rev it a couple of times and dip the clutch. hesitation coming and going on a 2 mile journey.

Checked fault codes.
Had 2 'pending' faults

P0170 fuel trim
P0172 Power train system too rich

Parked up,back to the car after 40 minutes and no power again. This time brought up a depollution fault on the dash.

Same fault codes but P0170 fuel trim changed status to current fault.

Also noted on the Torque 'emissions readiness' it shows the O2 sensor as 'incomplete'. However Ive never checked this page before so cant say if this is normal.

6 months ago the car got new coil pack,spark plugs and electrovavle chasing an intermittent EML fault.
Apart from this hesitation at pull away/low speed the engine pulls smoothly with power.

I had wondered if 6 months of lockdown short journeys (pretty much under 5 miles per day for work) could have clogged up the o2 sensor?

Cheers

[elcustardo]

I'm back! Son had Covid so we've been dealing with that.

Right havent really looked at the car as we have been home.
I had took it for a long drive and it improved the issue a bit. After clearing codes I was left with just P0170 code

Issue seems to be cold start dependant or at least much worse cold. When running fine the car runs perfectly.
Driving along it can lose power and requires dipping the clutch and blipping the accelerator to 'clear' the throttle and get the revs up

Had a visual check and dont see anything obvious. Had wondered if I had an induction leak giving unmeasured air in the intake.
Does this point ot lambda sensor? I recall years ago I had a car played up on cold but fine once warmed and that was the issue.

[GiveMeABreak]

I'm afraid I don't have anything on the EW7A engine codes - but P0172 generally indicates too much fuel in the mixture. The ECU can compensate up to a point, but this symptoms may become worse over time.

Generally, anything that can affect the mixture can be a suspect; fuel purge canister, worn spark plugs, faulty or worn oxygen sensor and the like.

Similarly for your P0170 - which means your fuel trim is out (either too rich or too lean), but beyond that there's not much I can suggest.

[elcustardo]

Thanks. Plugs/coils are new. Might go round and check connections on the MAF.
Got a feeling my wallet is in for some pain.

[elcustardo]

Does anyone have the part number for the correct MAF on a 2009 1.8 petrol?
Think I'll just swap it out as the car was near undrivable yesterday while cold.

[GiveMeABreak]

There's actually no MAF on this engine (I've removed reference to this in my earlier post),

P0170 Fuel injection: Malfunction
P0172 Mixture regulation: High stop

Not much info at all on this engine....

This is the Air Intake Throttle Valve Housing (Part: 1635X0)

[elcustardo]

Be honest. Ive not even been out. Mad times at home.
I did recall the Picasso had no MAF and I did have to replace the FBW throttle on that.
I had wondered if this was the same set up

[GiveMeABreak]

The thing is you don't really want to be replacing parts without being sure - and that may require further investigation / testing of the air intake throttle. It's annoying that they didn't bother with more extensive fault code data on these engines - they only seem to follow the standard OBD II codes and those one-liners aren't much help!

[elcustardo]

Cars sent to test me. Havent used it for a couple of days so went to my sons boxing (couple of miles)
on restart the car struggled to idle and had a flashing EML. think it was in limp home mode.
Checked the codes and it presented P0170 as current fault & p1336 as a pending fault. (Googling tells me crankshaft sensor indicated)
Restart cleared the flashing EML and the car idled normally. Drove away without issue

[GiveMeABreak]

P1336 is "Considerable misfiring on several cylinders: Not characterised"
P0170 is "Fuel injection: Malfunction"

But little else I'm afraid - except to say they are very well likely to be related - a fuel injection malfunction, causing misfiring.

[elcustardo]

Took a gamble and replaced the throttle housing.
I did buy it from a company who allow 'returns' with a cheeky hope if it doesnt work I could return.
cleared codes,fitted. Started the car and no EML lit or depollution error. Previously the error was there on start up.
Driving the car this evening so we shall see.
Reason I leaned to the TB is it seemed to impact the accelerator.
Worthy of note. My Picasso had the TB fail at around the same mileage of mid 60K.
If this is the fault on the C5,I wonder if its a common fault on lower annual mileage 1.8's

[GiveMeABreak]

This engine was also used on the earlier C5s, (EW7J4) and is similar to the EW7A used on the early X7s with the increased to 123 HP over the 115 HP of the EW7J4.

[elcustardo]

So car seems fine. No error codes stored or EML lit.

While im on. The battery clamp. I googled it and saw mention of bolted in lower clamps on the X7.
Mine however seems to have a clamp with a square drive hole?
Am I meant to use a socket extension on it or is it broken?
So as per this picture I dont have the plastic nut,just a square hole in its place

[GiveMeABreak]

Mine is the same. You’ll find a socket set wrench extension bar is the perfect fit to go into the whole and turn it slightly to tighten or loosen the battery clamp.

Put some silicone spray on it or grease and work it back and forth and you’ll find it a lot easier to use in future.

[elcustardo]

Just a follow up.
Car required a reset as the new TB was struggling to idle (symptoms like an air leak in the inlet side)
As I was doing the battery it was no drama. Working fine now.

I was concerned my new battery (correct for the car) was a smaller unit than the unit I was removing.
However since fitting I havent seen economy mode on the car at all, whereas previously it was on every time I got in the car and cut radio power a couple of minutes after switching the engine off.
Hopefully a prudent move for winter.