MAF type problems are back!

[boost30]

Hey Guys,

So I got an Ed30 a couple of months back and at the time of purchase I felt that the MAF was faulty. After running the car a couple hundred kms the CEL came up. The codes were as follows P0100, P0139 and P1602. The bloke at the shop that the car didn't sound too healthy on idle and that it was most likely the MAF. After some quick reading on the forum, I figured I'll change out the MAF along with a few other parts.

Cam Follower, Rev G Diverter Valve, Plugs, Coil Packs, Air filter mat (There was a really dirty K&N in it, so I replaced it with a stock mat), Engine Oil change and of course the MAF.
After doing all of this the car idled the way it should, she was so smooth and the power delivery was great! I was stoked  . Oh and obviously the fuel economy improved drastically. I was averaging 14-16 L/100km before and after a little TLC she was down to 10-11 L/100km (even with some spirited driving on the autobahn).

Yesterday on the way to work the problem came back. Basically it idles alright (around 700rpms) but sometimes its not constant and would dip or climb up.. Car feels quite unhealthy again and has a very bassy tone upto 3000rpm. She doesn't have that get up and go that she did after the parts were changed out. Also sounds like there is a fuel cut or something at times (this was also there before the parts were changed out), so when I put my foot down the power comes on kinda chokes for a moment and then back again. This is mainly noticed on stop and gos and not so much when I'm on the autobahn.

Basically, why would this come back? If it really is MAF related why would my brand new MAF be shot after no longer than 2 weeks on the car!
Also why would the car go from being healthy to her old self after a couple of weeks 

Any help would be greatly appreciated fellas.

Lil info about the car.

Edition 30
R8 coilpacks, NGK Platinum plugs, Rev G DV
85Tkm on the clock, Timing belt was changed prior to sale by the previous owner.
Manual Gearbox
FSW Catback Exhaust (Manuf. by REMUS)

Thanks in advance. 

[Dan_FR]

No mention of checking/changing the PCV......

[boost30]

No mention of checking/changing the PCV......

Hey Dan, Sorry that was my bad. I did the PCV check (where when the motor is idling you pull the dip stick out for a moment) and the idle went all haywire - which if I'm not mistaken is a sign of everything being in order.

[scopes]

Have you tried disconnecting your "maf sensor" and running some tests ?

[boost30]

Have you tried disconnecting your "maf sensor" and running some tests ?

I'll do that afterwork and update the thread. So if it runs better = sh*t MAF
and if it runs the same = not the MAF? 

[Pesky jones]

Are you getting any of your old codes?

A smoke test might not be a bad idea if you can get one done?

I'll do that afterwork and update the thread. So if it runs better = sh*t MAF
and if it runs the same = not the MAF? 

Not necessarily, but just see what happens

[Dan_FR]

Do you have VCDS? Check block 032 (fuel trims) and report back if so..... If you have recently cleared fault codes the car will need a number of miles driving to re-adapt. High or low fuel trims can indicate a leak or that there is a correlation issue between the MAF and Lambda sensors.

At the moment you have a code that indicates either the MAF or wiring is at fault, and another that indicates an issue with the rear O2 sensor or wiring

Ideally datalogging with VCDS would be the next step to understand what is going on

[boost30]

Do you have VCDS? Check block 032 (fuel trims) and report back if so..... If you have recently cleared fault codes the car will need a number of miles driving to re-adapt. High or low fuel trims can indicate a leak or that there is a correlation issue between the MAF and Lambda sensors.

At the moment you have a code that indicates either the MAF or wiring is at fault, and another that indicates an issue with the rear O2 sensor or wiring

Ideally datalogging with VCDS would be the next step to understand what is going on

Are you getting any of your old codes?

A smoke test might not be a bad idea if you can get one done?

I'll do that afterwork and update the thread. So if it runs better = sh*t MAF
and if it runs the same = not the MAF? 

Not necessarily, but just see what happens

Thanks for the input lads. Much appreciated! I erased the codes about 600km ago and the CEL has not come back on since. I will see what I can do about getting hold of a VCDS.

[Pesky jones]

Whereabouts in the country are you?

[boost30]

Whereabouts in the country are you?

I'm from Berlin, Germany.

[Pesky jones]

Oh, that's probably a bit too far from me 

[boost30]

Oh, that's probably a bit too far from me 

Yea! Thanks nevertheless.   

[Dan_FR]

If you can't find anyone with VCDS you can buy a cheap one for £20-25 that will do the job. It really is an essential piece of kit when trying to self-diagnose problems

[boost30]

If you can't find anyone with VCDS you can buy a cheap one for £20-25 that will do the job. It really is an essential piece of kit when trying to self-diagnose problems

Hey Dan, sorry if this may sound dumb but I have an OBDII scanner nothing fancy, just a normal one, but that won't give me fuel trims etc. will it? I've only used it to read out/erase codes.

[Dan_FR]

Basic OBD2 readers give fault codes only, which are great at 'pointing you in the general direction' of the problem. To pinpoint the issue and understand what the MAF and Lambda sensors are reporting to the ECU etc. means viewing live data over OBD2. There are various devices/interfaces that can do this, but VCDS is the favoured tool amongst most owners