In 2013 I had a flashing warning light & misfire, and the  main dealer had it  for 23 days, changing EGR valve, high pressure pump and tank-mounted fuel pump to finally cure it. Fortunately 1 week before warranty.

 

In early December 2015 the glowplug light began to flash on start up and as you drove down the road on cold days, but went off if you allowed engine to warm up and then turned engine off and on.

I assumed this could be a faulty glowplug, and that as water temp went above 5C plugs were no longer required, so turning off and on fooled it

Then the “control system for exhaust” warning light (not the “DPF” one) came on and stayed on for 2 days. Then went off

I took it to a local garage, who scanned for faults with a Snap On diagnosis tool, set to VAG system, (supposed to be much more detailed than EOBD) and it just came up with “exhaust fault, not any more detailed such as “sensor reading out of expected range” or similar

 

On garage’s advice I did 25 miles at 3500+ revs, what we used to call an “Italian tune up”.

All lights stayed off, then on 30.12.2015 when the “control system for exhaust” warning light came on and stayed on for a 60 mile continuous journey.  Car stayed in airport car park for a week, and when I drove back for the first 45 miles I stayed above 3500+ rpm, with no effect. I called into Skoda garage, and was advised to bring car in for diagnosis. Light stayed on for the remaining 15 miles, but when I started up the next day it stayed off.

The a week late the glowplug light began flashing on start up, and the “control system for exhaust” warning light came on continuously for half a day, then both went off.

The glow plug light stayed off for a week, then began to flash at start up, going off if you drove the car for 2 miles, and turned the engine off and on, like in December.

“Control system for exhaust” warning light has stayed off, however the glow plug light now occasionally comes on after the car has driven for several miles, apparently after the engine has been on overrun in a low gear down a long decline.

MPG seems to stay about the same, perhaps 5-10% down, but this could be blamed on the Italian tune ups.

 

Any ideas, suggestions, diagnoses before I take it to the main dealer.

You need to do a proper fault code scan with VCDS, not a generic Snap-On reader.

 

Each time the EML and/or glowplug light come on a fault code is logged.

 

VCDS is much more detailed and you can use this site to fully understand the issue and how to diagnose and fix...

 

http://wiki.ross-tech.com/wiki/index.php/Category:Fault_Codes

 

The exhaust pressure sensors are weak on the Octavia, the limited information from the initial scan would suggest it is one of the sensors.

 

You don't say what year your Octavia is or what engine is fitted, but if you have a DPF (Diesel Particulate Filter) then you shouldn't be leaving the fix as long as you have as the DPF won't be regenerating properly.

 

Get the car scanned ASAP.

 

If you don't want to pay dealer prices find someone on here close to you...

 

http://www.briskoda.net/forums/topic/224376-vcds-owners-map/

Edited 5 February, 201610 yr by silver1011