Fabia 1.2 no power/stalling/rough idle

[timo22]

A couple of weeks ago my engine management light popped on, I had it checked out and it was just an emissions out of range error. It was driving fine so thought nothing more about it although mpg has been noticably down.

 

On Friday, however, it suddenly had barely any power to give, idles very roughly between 600-1000 rpm (usually stalls) and fuel consumption is terrible. I've just tried to get it to a mechanic but it doesn't have the power to get up the hill. I've got a cheapo code reader which has shown:

16556 - fuel trim - system rich bank 1

17811 - EGR System Regulation Deviation (2 of those)

16687 - cylinder 3 misfire

 

Last week I also had a 16804 - Catalyst System; Bank 1: Efficiency Below Threshold.

 

From reading around those error codes I'm thinking it'll potentially be an O2 sensor (don't know which one), MAP, EGR valve or an air leak. Do those symptoms stack up and point to one of those in particular? It's a 2005 Fabia 1.2 12v.

[mrdaf]

Sounds like your rear exhaust o2 sensor. Before you do anything else, try a bottle of cataclean before you fill up next. It'll clean out your cat and improve your emissions. The o2 sensor helps with regulating fuel injection, and could also be causing the misfire by allowing too much fuel into the cylinder.

 

Wait until you've got less than 50 miles of fuel left, add full bottle of cataclean, after 20 or so miles delete error codes and go for another drive. Check for codes again after.

[Breezy_Pete]

EGR sounds to be sticking open, perhaps wide open, which may explain a few of your problems.  Here was my experience of this fault, albeit with far less drastic symptoms.

 

For the misfire, check spark plugs' condition, and if OK, swap the coilpack from cylinder 3 to another cylinder and see if the fault code changes correspondingly.

 

May be worth checking the chain timing too, details of one method in the above-linked thread.

[timo22]

Please bear with me, I'm new to all this...

 

Thanks for the help so far. Due to being really busy the car is still sat on my drive and the saga continues after having some work done. Had a new lambda fitted although they put it in the front one, just seen you said rear and read up on what bank 1/bank 2 means. Doh. Does the Fabia just have bank 1 and then S1 and S2? Their code reader might have given more info on which one though. EGR was really clean. Spark plugs were horrible so got new ones. The guys replaced coil pack 3 and did VCDS things like compression tests - all fine. Still have the same problem; occasionally it'll idle although but fairly stable for a bit but won't rev past 2.5k then goes really rough and dies. Now no management light or fault codes are appearing. 

 

The battery died so I charged it up, got one start, crap idle and stall out of it and now it won't start up at all (I'm sure the battery is fine, reads 12.7V on my meter). If I hold the key right round when starting it shows very low revs, is this just the starter motor spinning it? If so might I have now got two or three blown coils and could the bad idle, no power and stalling problems just been caused by only two cylinders firing? I don't want to bundle straight into buying more coils to find that's not the issue.

 

I've just checked the timing through the inspection holes (as I've been dreading that being the issue) but that seems fine

 

Any help much appreciated!

[Breezy_Pete]

Your engine has just one bank of cylinders (B1), and uses two oxygen sensors, one upstream of the cat (S1), one downstream (S2).  The upstream one is a wideband type which should do a good job of letting the ECU know in real-time exactly what residual oxygen is in the exhaust gases, to give it the best chance of getting the fuelling right. The downstream one is an old-technology narrowband sensor, purely monitoring how well the cat is cleaning up the exhaust, a European legal requirement after a certain date.  it doesn't directly control the fuelling at all, it just warns you that your cat is apparently failing to do its job. This may not be because the cat is 'sick', but possibly due to more global engine problems like misfiring, which throws the ECU's attempts to regulate fuelling into disarray.

 

TBH with you, I don't understand how it can be misbehaving as badly as it is without showing any fault lights or logging any codes. Sorry I can't be more help.

 

Maybe check the wiring to the coils for damage, or loose/corroded earths?

 

The EGR may be immaculately clean but still misbehaving, keep an eye out for that 17811 code returning if you can get the car running well enough to drive for a while.

[timo22]

Just found it's an exhaust blockage, got it running by removing the front lambda so the exhaust had somewhere to go.