Hi all,

I have mentioned this as part of a couple of other threads so it's all become a bit spread out, so thought I'd summarise the current status of the problem here, and hopefully get some advice from you guys

On Friday morning (just passed), I replaced all 4 coil packs on my Octavia VRS Mk 1 ....... no issues, and car running fantastically after it ......... >

On Friday afternoon, I had the car remapped, with an Elite Remaps map ......... no issues after the remap and car running beautifully.

About 4 hours after the above, I got the CEL (engine warning light) on, on the car.

I have :-

- Checked brake lights, as per a suggestion on another thread,

- Generally checked the engine bay, including removing coil packs again, checking spark plugs (no fouling and looking healthy), refitting coil packs etc,

- Disconnected the battery for 30 mins,

...after the battery disconnect, sure enough the CEL light went out .... but came back on 2 hours later. I've since tried a further reset and again it went out after re-connecting the battery, but subsequently came back on.

I have ordered a OBD Code Reader, which I am now awaiting, so will eventually be able to check for errors, but in the meantime, can anyone suggest any tips or advice ?

I read somewhere about a 'temp sensor' that often goes, making the engine warning light come on ...... can anyone tell me where that sensor is ?

Is it possible that the remap is taking some ECU reading beyond it's normal parameters, and maybe I'm always going to have the CEL light on ?

As I said, I am awaiting the code reader but in the meantime, would really appreciate any advice........... oh last thing to say is the car is running beautifully. No suggestion of any issues or rough running... just this pesky CEL light staring at me

Many thanks for any help. :sun:

Edited 6 May, 201214 yr by Longyear

wait for the code reader and scan it

the sender you're referring to is the CTS [coolant temp sender], plenty of threads here about it

as for the map, how many miles has it covered in these 4 hours you mention ?

on a sidenote: if you ever want to reset a fault code more rapidly than the 30 min procedure: disconnect battery negative, turn key in ignition to pos 2, leave it for about 10 secs, remove key and connect battery

Unfortunately there's no point in even beginning to guess what it is yet I'm afraid. It could literally be anything!

A CEL after a remap isn't right. I'd get back to the tuner and let them have a look.

Did the tuner test the car on a road or rolling road?

wait for the code reader and scan it

the sender you're referring to is the CTS [coolant temp sender], plenty of threads here about it

as for the map, how many miles has it covered in these 4 hours you mention ?

on a sidenote: if you ever want to reset a fault code more rapidly than the 30 min procedure: disconnect battery negative, turn key in ignition to pos 2, leave it for about 10 secs, remove key and connect battery

Cheers. I drove about 20 miles following the remap, before the engine light illuminated. The remapper assures me he's put the map on 30+ cars identical to mine and never had a engine warning light on as a result .... and the fact that the coil packs were changed shortly before the remap does lead towards that being a factor too.

As you say, the code reader will give a more definite indication as to whats going on ........ just have to wait 3 days for it to arrive!

Cheers.

Unfortunately there's no point in even beginning to guess what it is yet I'm afraid. It could literally be anything!

A CEL after a remap isn't right. I'd get back to the tuner and let them have a look.

Did the tuner test the car on a road or rolling road?

Yes, the tuner is a friend of a friend and thoroughly tested the car before and after. As above, the car drove for around 20 miles post-remap, without the light ... the light then came on. Cheers.

20 miles is a reasonable distance for it to be caused by the map... or it just may be some coincidence

you'll find your answer in 3 days

Yeah, cheers ..... patience is a virtue!

This forum is gold dust ........ I've found two jobs to do tomorrow, that I wouldn't otherwise have known about;-

- Reset spark plug gap (which is definitely currently on 0.8mm), to 0.7mm, now that car is remapped.

- Going to inspect my CTS sensor to see if it is an earlier black one, or a newer green one........ to consider potential replacement.

Cheers.

Edited 6 May, 201214 yr by Longyear

Did you sort your CEL light issue?

I have a similar problem and am interested in how you sorted it.

Also would it fail an Mot with that light on?

Also would it fail an Mot with that light on?

Probably depends on the tester. My old Volvo failed with the Lambda light, but that was so glaringly obvious.

Not so obvious after I removed the bulb though. (shhhhhhh)

Did you sort your CEL light issue?

I have a similar problem and am interested in how you sorted it.

Also would it fail an Mot with that light on?

Hi - yes, the CEL light has been 'off' for a week now; The car was put on VAG-COM and the issue was two dodgy coil packs that were only replaced 1 week earlier! (beware cheap patterned parts from cheap motor factors)..... I bought 4 VAG coils from Awesome GTI (the red ones) and the CEL light has not been seen since ....

However, my next problem (I've had my Mk 1 VRS for 3 weekS and it's been a catalogue of problems so far), is a 'stutter' in Turbo performance, under mid-load (ok, under heavy load).... but I am going to start a new thread about that issue, hoping for some pointers. I'm confident the 'stutter' is turbo related, rather than ignition. No faults logged on VAG-COM but a definate 'stutter' in boost. :(

Cheers.

Edited 18 May, 201214 yr by Longyear