I have a 1.416v Fabia estate

for the last 15k miles the engine management light as been permanently on and the engine is pinking slightly, it has been on VAGcom and it reads 'restricted flow', I have changed/done the following:

EGR valve

fuel filter

air filter

spark plugs

cleaned and checked all pipes, ie EGR and air in

checked exhaust back pressure for blockages

head was looking a bit gummy so did an engine flush

I think that is all, but what am I missing, it is driving me to distraction?

thanks

Not much more to offer really but how about this -

16785/P0401 - Ross-Tech Wiki

Obviously ignoring the DPF parts.

Changed the HT leads too?

What about the valves maybe gumming up. I can't think of much that you have not already tried.

HT leadsgood thinking, thanks could be worth a try...

thank's guys, at least I know I have tried most things...will look into valves/head

Not much more to offer really but how about this -

16785/P0401 - Ross-Tech Wiki

Obviously ignoring the DPF parts.

thanks for that, very useful

If you're sure it is pinking rather than something else only a good long hard run will clear it for a while.

Do you do a lot of mainly short start stop journeys this is the main cause and if you drive like a granny or frugally it will just come back.

The timing can cause pinking but if your car has an ecu all the timing is adjusted by that.

What condition/colour were you spark plugs in..??

Check this thread

My Cousins Fabia had its Engine Management and EPC light lit a month after buying.

Had the computer read at a garage and then had the throttle valve cleaned.

But the lights lit up again a week later

Changed the Temp sensor and all is well.

If you're sure it is pinking rather than something else only a good long hard run will clear it for a while.

Do you do a lot of mainly short start stop journeys this is the main cause and if you drive like a granny or frugally it will just come back.

The timing can cause pinking but if your car has an ecu all the timing is adjusted by that.

What condition/colour were you spark plugs in..??

sorry to have only come back to this today have been away

deffo pinking

done plenty of long runs but most of the driving is short journeys

the spark plus were mullered, new ones seem to have lessened the pinking but the engine light is still on

mechanic did say the head looked quite 'gummy' when he changed the plugs...

thanks

I know they get blamed for everything, but I assume you are aware of the piston ring problems on the 1.4 16v engine (especially AUB/AUA engine codes). Worth a look? Try a compression test perhaps?

I know they get blamed for everything, but I assume you are aware of the piston ring problems on the 1.4 16v engine (especially AUB/AUA engine codes). Worth a look? Try a compression test perhaps?

yes aware of potential problem, I thought sign for this was excessive oil useage and our car is well within tolerences etc

my gut is a coked up head something like that

many thanks