Fault codes, Is this the MAF?

[SeanyK]

Hey!

So the other day, I saw the fault light come on, thought it was coils, it wasn't.

Cleared it, it came back yesterday after I released the throttle at about 70mph.



I did some VAG-COM logs with my mate and it says this;

1 Faults Found:
17536 - Fuel Trim: Bank 1 (Mult): System too Lean
P1128 - 35-10 - - - Intermittent


I went through a couple of the usual measuring blocks, here are the results;


Group 032 Lambda -4.1% lambda 21.1%




MAF readings;


82.2 g/s was the peak I saw on log 002 for MAF redlining in 2nd Gear
Idling it is 3.33 g/s

Idle says 20.3% load Inj.on Time = 2.05ms


According to the VAG-COM site, a standard car should be about 120 g/s at redline.

A chipped car, should be anything up to 180 g/s.


Peak airflow should be roughly 0.80 x bhp of car

Mine is revo'd, let's say its 180bhp = 144 g/s

So 82.2 g/s is rather low!



Question is, is it this low because it is in limp mode (clearly it is in limp mode due to speed!)?


Im gonna change the MAF on Monday/Tuesday and see if it brings any joy.

 

[ibizacupra]

yep. muchos low g/s

suspect MAF first yes

 

[Black TDI Turbo]

Try disconnecting it and taking it for a drive should improve and feel much better, question to bill, when disconnecting the maf it makes it go better but does it go into a default setting when the maf is disconnected, as i would have thought when disconnecting it the performance would be worse?

 

[Black TDI Turbo]

When you say peak 82g/s was that 3rd gear full throttle? how did you do the logging?

 

[ibizacupra]

with no maf sensor signal the ecu uses other tables to look up from... typically running richer than an under reading poorly maf... so goes better, but usually overfuels.

 

[Black TDI Turbo]

yeh hence why it shouldnt be just disconnected and left off.

 

[SeanyK]

Hi guys, firstly, thanks for the replies

I did the log by basically driving it to redline/full throttle in 2nd gear, and my friend checking what it was at during the redline which was 82.2 g/s.

Car has done 65k, so it's pretty likely the maf needs changing as it hasnt been changed before.

Where is best for a MAF, I know it has to be exchange, I think my local ECP has them for £55 exchange, and I'll just swap it over in their car park.

Unless there is a cheaper place? I could call GSF on Monday, im doubting any VAG dealership would be cheaper...

 

[Black TDI Turbo]

try doing the run again in 3rd and 4th gear puts the engine under higher load i know the speeds do increase alot tho so on a private road of course

 

[ibizacupra]

if its only reading that airflow on 2nd gear pull, ity is'nt going to get any better trying it in 3rd is it.

maf = fcuk'd

 

[SeanyK]

Im gonna replace it anyway, as 65K seems longer than a normal one would last given they are prone to failure.

I'll report back with the findings on Monday/ Tuesday depending when I can get to GSF or ECP.

 

[p34ch3y]

i just got this at the weekend myself (17536) too

 

[SeanyK]

Hey folks,

So I changed the MAF over yesterday, drove it home, no different (I hadnt cleared the code though!)

Put VAG COM on it last night, went to log the g/s noticed the light had gone out with the cable connected, even though I hadnt cleared the codes which still came up on the report thing.

Drove it, got about 145 g/s in 2nd gear full throttle run so that seems right now.

I cleared the code, and hopefully now it won't be back!

For reference, the MAF cost me £65 inc VAT from Euro Car Parts, that was exchange, so you need to give them your old one at the same time, but it's easy to just change it over in their car park.

 

[p34ch3y]

so what you saying sean that this is the maf?

 

[RichN]

I also had this come up today. Cheers for posting, I hope to check g/s flow tomorow.

My vac hoses are on the way out (one from top of DV is looking shabby, that is) could a split here have caused this, or would a split top hose cause more noticable issues?

Cheers again folks

 

[SeanyK]

P34ch3y > It was in my case, however, it can't really be confirmed unless you log the g/s flow on VAG-COM that way you can get an idea of whether the MAF is functioning correctly.

RichN> It's possible mate, any sort of vac leak throws up an error code, I happened to get a secondary air valve code thrown up as well the other day, but it was as clear as day as the braided hose had a split through, so I replaced most of my VAC pipes just for the sake of it, as it saves a job later on And it's very cheap to buy as well.

I'd advise you to just replace them out of process of elimination, the braided ones seem to need changing after about 3 years onward.
The majority of the vacuum hoses can be replaced very quickly.

Instead of trying to re-use the clamps SEAT use, just use cables ties on the new ones to tighten them (trim off the excess to keep it neat).

 

[RichN]

RichN> It's possible mate, any sort of vac leak throws up an error code, I happened to get a secondary air valve code thrown up as well the other day, but it was as clear as day as the braided hose had a split through, so I replaced most of my VAC pipes just for the sake of it, as it saves a job later on And it's very cheap to buy as well.

I'd advise you to just replace them out of process of elimination, the braided ones seem to need changing after about 3 years onward.
The majority of the vacuum hoses can be replaced very quickly.

Instead of trying to re-use the clamps SEAT use, just use cables ties on the new ones to tighten them (trim off the excess to keep it neat).

For the record and anybody searching this in the future, complete replacement of all my Vac hoses has indeed stopped the car running like crap, and so far the engine warning light remains off. Fairly sure it's sorted.

Did also log the g/s results from MAF and found it peaked at 100g/s no matter what I did. I assume this is FAR from what it should be (car is essentially standard) and I'll be off to GSF or ECP tomorow.

Cheers again.

 

[p34ch3y]

chek this out

this code turnd out to be......................yep you got it the MAF