Hello people, been lurking for a while but this is my first post, so I hope it's in the right place.

I've had my Octavia VRS '53 plate for about 8 months now and I've been having problems with my enigine mangement light, it says that the system is too lean. Took it to my mechanic who looked over it and said it was a vacuum pipe which he found and replaced.

A week later and the lights back on so I took it back to him and it's the same fault. He's looked over it again and found nothing else wrong. It drives okay and he says it doesn't seem underpowered and if there was something serious it would cut the power. So for the last few months I've been living with it.

I saw him again today and got him to check again to see if it threw up any new codes but it's still the same, so he cleared the code again. Driving it home it felt a bit weird the throttle response seemed to really lag and be fine the next, but the lights still off for the moment.

Does anybody have any ideas coz it's starting to wind me up!

The fault code is 17536 or VAG code P1128, it says Bank 1 Fuel Trim System Too Lean.

Any ideas would be appreciated, cheers.

It could be drawing in unmetred air from somewhere, or it could be the MAF sensor.

Here's what Ross-Tech say about it: 17536/P1128/004392 - Ross-Tech Wiki

Cheers mate. I had an idea it could be the MAF. Don't suppose you know how if I can check the MAF myself without forking out for a new one do you?

It's not an easy one unfortunately, if you MAF was totally fubar then unplugging it and then seeing if the car drives any better is usually a good one. But if your MAF is working but not properly, it won't be much help.

Where are you located? There might be someone local with a vRS who can help you by swapping theirs and taking it for a run perhaps?

That sounds like a plan, I'm in Reading. I know there's one that parks a couple of miles down the road from me, but rolling up to their door and asking to borrow part of their engine is prob a bit much!

I had the same error code when my aftermarket TIP had come off the turbo. In the process the MAF also failed, possibly as part of the system trying to compensate for the strange readings it was getting?

New MAF and a big clamp on the pipe fixed it.

Thanks for the info Rob. I've checked the pipes and I can't seem to find any splits but I'm no expert.

I've also bought a used but tested MAF to see if that would help. Does anyone know if I should expect the code to clear straight away if the MAF is to blame or would it take a bit of driving first, similar to the way it comes on after being cleared?

You'll need to clear the code first, then drive it around for a bit and see if the code comes back and the light comes on or not.

If you've got someone near you with VAG-Com you could check what the MAF readings are and compare them against those on a vRS with a MAF that is definately ok.

The MAF reading should about 150 g/s at WOT on standad rs. Mapped is around 180 ish.

HTH

Thanks mate. Got my mechanic coming over tomorrow morning to clear the code. then I guess we take it out for a spin and see what happens.