I've replaced the following things lately on separate occasions as they had failed:

Rocker cover breather hose

All coils after 1 failed

and last night, the hose from PCV valve to inlet manifold

 

After doing each of these, the car has thrown a bit of a wobbly for a couple of days, e.g. rough(er) idle, on occasion throwing a MAF error, then settled down.

 

I'm guessing this is to do with the was the ECU learns to run for it's given conditions, and when I change those conditions e.g. by replacing a leaky hose, it has to a) realise that and adapt to it?

 

I was wondering if it's worth clearing the ECU learnt values by disconnecting the battery? (I don't have vagcom)

 

 

Does anyone know if doing that would require a TBA? I haven't been able to find a definitive answer so far... that's the only thing stopping me just having a go at the moment

 

Cheers

 

 

 

EDIT: That wasn't supposed to be a guy in sunnies, but whatever, I can dig it

Edited 22 August, 201411 yr by James19181

The ECU will adapt to any changes over a few driving cycles.

Poor idle can be caused by a number of things. CTS, MAF, vacuum/boost leak, dirty throttle body are the usual culprits.

I wouldn't expect a MAF error to be caused by the parts you've replaced.

Have a look on the VCDS section of this forum as there's probably a member near you who will help you out for beer tokens.

If you intend keeping the car I would invest in a eBay OBDII cable & download VCDS lite ($99 to register with Rosstech which opens all the functions). Mine has paid for it self many times over.

Edited 22 August, 201411 yr by pauldazzle

Hi Paul,

 

Cheers for the input - I might just leave it alone then and let it sort itself out. Unfortunately, living in Guernsey, there's nobody near me with VCDS!

 

I have a code reader which came with an OBD-USB cable as well - So I'm guessing I should be able to use that with VCDS lite. TBH I didn't realise registered VCDS lite allowed you to do TBA etc. so I'll go and have an investigate - the code reader has already been well worth the £30 that cost.

If you already have an OBDII cable you can download vcds lite for free, & it should work.. It'll do basic stuff including tba I think, but it's well worth paying the $99 to open all the features. TBA is no big deal to be honest as the ECU will self adapt over a few driving cycles.

If you haven't cleaned the TB yet I strongly advise that you do it.

Vcds lite wont do TBA or any other adjustments. Its just a code reader really but well worth downloading anyway

If you haven't cleaned the TB yet I strongly advise that you do it.

 

Funny you should say that, ordered a TB gasket this morning so I can do that  

Vcds lite wont do TBA or any other adjustments. Its just a code reader really but well worth downloading anyway

I registered my VCDS straight away so never actually experienced the limitations of the free version.

I registered my VCDS straight away so never actually experienced the limitations of the free version.

Ive not registered mine yet but keep meaning to. The free version just serves as a code reader but very worth while having regardless

$99 to register is well worth it & it's a good exchange rate at the moment.