Misfire and stuff on 04 C5 2.0i (not hpi)

[deian9]

Hi all (some of you may know me from the past, glad to be back, can't stay away can I),

So I purchased a 2004 C5 2.0i (non hpi) exclusive, it's a nice car, and a step up from a xantia (i never knew i'd say it), but paul did mention to me before that a C5 is a better car.
But typically it has a few problems, which I will list... (then I'll list what i've done):

1) Misfire, which stems from the injector of cylinder 1, i put a screwdriver to it and it doesn't click like the other three. Sometimes it runs on 3 cylinders when it happens, sometimes 2 cylinder, which is annoying.
2) The interior lights (the courtery lights, not the passenger ones that point to the corners) seem to do what they want sometimes, I once locked the car and a neighbour gave me a knock to let me know the interior lights were on, I had to try a few times to switch them off, it seemed the rear lights were on.
There's been a few times when I've started the car and they come on randomly a few times until I switch them off with the middle button a few times (I actually yelled many a profanity at them to get them to adhere).
3) Gearbox works, sometimes gets a bit confused when it misfires.
4) It's fine when cold, and then as soon as it gets warm (usually everytime I get to a certain point in a very particular journey, you can pretty much bet money on when it will start to misfire).
5) Possibly realted to whether I go round corners or up/down hills, but hard to tell.
6) Braking hard at high speeds it seems to judder quite badly sometimes, but when it doesn't I don't notice it. But this may be due to warped discs as it has new discs when I bought it and maybe they weren't bedded so gently. But it almost seems like the ABS pulsing, again not sure.

The faults it complains about in the following order (as it gets used more and more daily) is:
a) Anit-pollution fault - this could be anything right.
b) Catalytic converter fault - this comes on after a longer run and the engine light flashes when it comes on
c) ESP/ASR fault - this comes on if i ignore the flashing engine light due to the above
d) Tyre defalted and 3 tyre sensors missing - probably unrelated, I can live with this one if it's not causing the others.

Fault codes off my OBD2 reader:
P0300 - random multiple misfire
P0202 - injection circuit / open cylinder 2
P0141 - 02 sensor heater circuit bank 1 sensor 2

What I've done is a BSI reset a few times, to the letter. No joy, cleared the faults with my faultcode reader. Had a Lexia session with PaulR (many thanks), no real clues there as it may have stored some old faults which needed clearing. Haven't been back for a second session since.

Battery checks out ok, a good voltage when off (12.6 V), and has (14.4V) when running off the alternator. Not sure how well it maintains power flow (and voltage) under load, i.e haven't done a shunt test to check the charge.

Guesses:
- Either a lose/corroded connection on a common earth related to the oxygen sensor. Which then throws off the other faults.
- Catalytic converter fault due to not receiving the correct values between the two oxygen sensors?
- Anti-pollution fault due to running rich due to the oxygen sensor not heating?
- Lose wiring related to injector and oxygen sensor before the catalytic converter?
- Intermittent failing cell in the battery (althought I think not in this case, I have no other source of a spare battery to swap and eliminitate this at the moment).
Not sure how it's related to the interior light being weird too, maybe through a common earth?

Everything else seems to work fine as far I can tell.

Other than that I like the car, it pulls well when it works. And rides nicely. But I just can't work out these fault. So before I rip out some computer and checking some wiring does anyone have any ideas? I have no wiring diagrams for this one, so if anyone has anything for me to chew on it would be much appreciated.

Thanks,
Deian

[GiveMeABreak]

It may help if you post up your VIN so we can identify the specific car. Here are the Citroen descriptions for these fault codes:

P0300 Combustion misfiring on unspecified cylinders fault : Not characterised
P0202 Injector 2 control fault : Open circuit, short circuit to positive, short circuit to earth
P0141 Downstream oxygen sensor heating control fault : Open circuit

[deian9]

Hi,

The VIN is: VF7**************[VIN obfuscated, can be read by forum staff] 76392382

How hard would it be to get the downstream oxygen sensor out? I can see it clearly, but will it be pretty much welded on after all this time?
Does anyone have some electrical characteristics or pin out for it so I can test it? It's outer sheath is frayed where it clips into a rubber gromet holder, but the wires themselves 'look' undamaged.

Funny thing about the injector 2 fault, as it's clearly injector 1 that I can't hear clicking, injector 2 clicks away fine (unless when that one fails, it goes to running on two cylinders). Are they somehow daisy chained and there's a break at injector 2 which leaves injector 1 open hence not working? Are they earthed by the body of the injector or by the one of the two wires?

Thanks

[CitroJim]

Hi and welcome back Deian Great to see you

If you want, we could potentially reactivate your old account and perhaps even merge this topic into it... Let us know in due course... Right now I can't recall your old username...

[deian9]

Hey,

Thanks Jim, I can't recall it either, I tried to sign up with my old username of deian but it failed so it may be dormant somewhere, so it could be that. But for now, I'm happy to leave it as it is. I just have an internet purge from time to time and comeback slightly different (like Dr Who lol). I'm glad you're still about and keeping well.

So it seems the C5 is beyond me, but I won't give up. Awaiting some ideas...

[Hell Razor5543]

One thing you might want to check is the little rubber pipe that links the metal pipe and the EGR valve (in the area of the bulkhead, drivers' side). If this leaks that could cause the Anti Pollution fault (it did on my C5). Fortunately the leak was at one end, so the friend who spotted it trimmed the rubber pipe back by 1cm (past the pin hole leak) and she has not complained about it since.

[Paul-R]

Hi Deian, glad to see you made it back here.

Is the oxygen sensor the same as a lambda sensor? My daughter's Pug 106 failed the MOT and I bought replacement sensors for it but the threads in the manifold and catalyst were both old and crumbled away. So be careful taking them out.

The story with the 106 got worse as it's the less common 16v version and I had a heck of trouble getting a manifold and catalyst for it. I ended up driving to Sheffield and back just to get replacements.

I left the sensors in the replacements (no way was I going to take them out!) and hoped that it would pass the MOT, which it did after getting the engine stinking hot. In fact I still have the new sensors if they're the same as yours (and you get yours out).

[wheeler]

Do you have a make of the Oxygen sensor (yes, sometimes referred to as lambda sensors) ? The heater elements (pins 1 & 2 of the connector) have different resistances varying between 3 ohms & 11.1 ohms depending on make.
Why don't you try swapping the injectors around with each other to see if the fault moves with them. The injectors get their shared power supply from the under bonnet fuse box & the injection ECU earths them to operate them.

[Paul-R]

My Cars: old ones in no particular order

You forgot to mention that wonderful Toyota Corolla that you were always singing the praises of.

[Paul-R]

Do you have a make of the Oxygen sensor (yes, sometimes referred to as lambda sensors)?

If that was directed to me then I'm not sure at the moment as they are at home and I am not. I bought them from Euro Car Parts and I'm fairly sure they were packaged in boxes with Italian words.

[deian9]

Paul, I'll have a look, I think I recall four wires to my O2 sensor. It is the same as a Lambda sensor as Wheeler pointed out. I believe it's to do with the fact that its there to maintain a balance which in this case is the air/fuel ratio (which i think is 14.1, or is it 13.7). Anyway. I'll bare that in mind if I smash up the sensor for whatever reason. For now I'll check the wiring for continuity.

I'll look into swapping the injectors too, but maybe I'll find some wiring issues when I open up the wiring cover near them. If the fault is detected at injector 2 and injector 1 is faulty, then this could lead to the solution.

Thanks for the input everyone. Does anyone know what wire is what for the injectors? Bit of a long shot, but I could do with some wiring diagrams if anyone can be bothered. I could guess and eliminate, but the weather doesn't help.

Oh and Paul, yes that Corolla worked, it was a shed, leaking piston rings led to it's demise (common problem on some), I bought it as I had enough of a complex world as I neared the end of my degree, but soon realised I like the complex world, so here I am, with a C5! Oh I am still holding a thought for that RF exciter for the wheel sensors.

[GiveMeABreak]

Hi,
How hard would it be to get the downstream oxygen sensor out? I can see it clearly, but will it be pretty much welded on after all this time?
Does anyone have some electrical characteristics or pin out for it so I can test it? It's outer sheath is frayed where it clips into a rubber gromet holder, but the wires themselves 'look' undamaged.

Funny thing about the injector 2 fault, as it's clearly injector 1 that I can't hear clicking, injector 2 clicks away fine (unless when that one fails, it goes to running on two cylinders). Are they somehow daisy chained and there's a break at injector 2 which leaves injector 1 open hence not working? Are they earthed by the body of the injector or by the one of the two wires?
Thanks

Magneti Marelli multipoint Injection System 48p
EW10J4 Engine
Downstream Oxygen Sensor for this engine Bosch Ref: OZA 341-PG7 (6-way black connector)
Any other info needed? (I'll dig out the wiring for this sensor in a tick).

[deian9]

downstream is from the exhaust manifold into the cat right, i have four wires going into a blue plug near the egr valve?

[GiveMeABreak]

1303 is your signal from Lambda sensor C (-) downstream of the Cat.
1302 is your signal from Lambda sensor C (+) downstream of the Cat.
124 is the control heating Lambda sensor C downstream of the Cat.
1351B is the Lambda sensor heating power supply.

This should be a 4 pin Green connector (although the info in my last post says 6 way black) - so you'll know which is right!

[GiveMeABreak]

5 Pin Black connector:

1253 is your all or nothing solenoid valve (EGR)
1254: EGR Supply
1220: throttle potentiometer Supply 5V
1346: EGR Repeat sensor signal
1257: EGR Solenoid valve Earth
1373: Linear EGR control valve