High/lumpy idling + a nice yellow warning light.

[alextrea]

Alright,

I have a problem.. Again. So i thought I'd come to you lot for advice to see if some knowledge could be shed. I have 06 GTI, 77k miles running an EVOM intake and milltek cat back and standard map.

Engine warning light came on couple of weeks ago and diagnostics showed it was running lean and the first lambda sensor was shot. Changed the lambda a couple of days ago, car was running fine.

Today, however, it's decided to come back on with the same symptoms as before, rough lumpy and high idling.

Anyone had the same problem or know what could be wrong?

Any help would be great as I want my car to stop being poorly :(

[th3_f15t]

Have any recent diagnostics told the same fault codes? Could be wiring more than the sensor itself. Other problems could be a faultly PCV or broken HPFP cam follower, neither of which will throw up a code but will effect the engine running.

[ruhaleali]

Have you checked the coilpacks could most likely be that!

[Degudodger]

Alex - Where abouts are you.

Might be worth checking the VCDS owner register to find your nearest member with VCDS who can do a quick scan for you. http://www.mk5golfgti.co.uk/forum/index.php/topic,88875.0.html

[Mrstridey]

Hi, had a similar problem and it was a silly little bit of plastic on top of the engine (valve) that had gone wrong and wasn't sealing properly.

When you turn the engine off do you get a hissing noise from the engine (might need 2 people)?

If yes try swapping the plastic bit, costs about £40 ishhh

Hope this helps!!

[alextrea]

Fault code coming up is b3800 ... Any ideas?

[alextrea]

Turns out it's a faulty tumble flap.

Could this be caused by a rather large intake damaging the flap?

[th3_f15t]

Probably, yeah... Will have put it under extra stress.