Hi guys I posted a few days ago asking for advice on my vrs when I'm driving or overtaking the car was hitting some very bad flat spots I was told the cat was blocked. After having it de-catted today its no better I've serviced the car new plugs etc and had it on the diaganostics and it only came up with a catalyst code which was done I'm lost for ideas can anyone help thank you

Im not suprised it came up with a cat code if it doesnt exist anymore

Came up with cat code b4 I removed it

clean the TB?

what about lots of crap in the IC and pipes?

is it remapped at all?

Tb? Ic pipes ? Lol. No not remapped as far as I'm aware my mate has vag com or sumthing that he is going to plug in see what he comes up with.

Is it this code?

http://wiki.ross-tech.com/wiki/index.php/16804/P0420/001056

Have you had the code cleared and then tried driving it? Sometimes the car won't run right if there is an old fault code stored until the code is cleared

TB = Throttle body

IC = Intercooler

there you go mate, agreed with Chicken too, they are buggers for that. What about leaks? might be a small pin hole in the pipes?

I am stumped lol, best to wait till your mate looks at it with VCDS

Going now so wish me luck thanks folks.

No codes at all so I'm mega stumped

As Billy said in an earlier post try a throttle body clean, easy and cheap DIY job:

http://briskoda.net/forums/topic/129943-cleaning-throttle-body-1-8t-engine/page__p__1631514#entry1631514

You can check if it's been remapped by logging the peak boost with VAG-Com, I think VAG-Com gives it in millibar plus 1000 mbar of atmospheric pressure so the peak boost you're looking for on a standard car is around 1700mbar (0.7bar, or 10psi), if it's 2000mbar (1 bar, 14psi) or above it's remapped.

Thank you I will give that a go I'm at my witts end lol

Told if it aint the tb which the mechanic sed he doubts he says it cud b a map sensor ?

MAP (manifold absolute pressure) or MAF (mass air flow) sensor?

If it's the MAP sensor I'd expect there to be a fault code. If I remember rightly the sensor is plugged into the top of the intercooler underneath the drivers side headlight/indicator so you could visually check if it's come unplugged.

If it's the MAF sensor you can unplug the multiplug from it and see if it runs any different with it unplugged if no difference then the MAF is probably goosed. If you can borrow a working MAF off of another 1.8T car this should confirm. The MAF is the bit between your air box and turbo with a multiplug going into it:

http://www.ebay.co.uk/itm/AUDI-A3-2002-1-8T-AIR-FLOW-METER-MAF-SENSOR-06A906461L-/390351632268?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5ae2c5378c#ht_2119wt_1110

Thanks so much for the advice hope I get it sorted

Was gonna say it could be plugs but you have changed them.

Might be coil pack breaking up under load - I have some spare ones if you want to try that

Thanks stskoda wud they not come up on a computer check ? Also ru local to me ?

Contact your dealer as they can replace the lot for free usually under a recall.

dealer can do free recall if your have genuine coils - if not pm me

from what i've been told they don't always come up on a scan - general rough running is a symptom through - do a search on here for more info

Great stuff , how would I go about this recall and how will I know if the parts are genuine cheers.

This might sound daft, but have you had your brake light switch checked, or is there a code for it...??

It is dual circuit (lights/ECU) and will kill the revs sporadically if playing up...

Skoda Dealer will check coilpacks FOC and replace if genuine faulty variety fitted. Had mine confirmed ok on recent oil change. I had already checked them as was having similiar problems to you which ... turned out to be a faulty brake light switch....

Hi no faults at all come up :( I will try that aswell m8

Where is it located?

Where is it located?

Under the dash below the steering wheel cowl, there is a sound proofing / trim. Remove it carefully - it's tricky to replace. The switch sits on the brake pedal. They are known to go but usually take out the brake lights, which mine didn't. Mine rattled, ten quid for a new one.

Thanks guys I'm gonna give all these options a look over next week I appreceate the help and advice and hopefuly I will get it sorted I will keep you all posted.

Remove & clean the throttle body & go from there.