Might be in over my head....Help needed

**JumboBlack1.8** · 06-19-2008 04:41 PM

So, after almost 6 weeks of waiting, my car is FINALLY driveable. Got her back from the exhaust shop today to mate up my custom downpipe with the rest of my Milltek exhaust. However, from the first time I started her up, I got a VERY rough, fluctuating idle, which eventually sustains at around 900rpms when it warms up. Also, I'm getting a CEL for the MAF....

VAG-COM Version: Release 409.1-S
1 Fault Found:
16487 - Mass Air Flow Sensor (G70): Signal too High
P0103 - 35-00 - -

When driving around, the car drives just fine out of boost (aside from some nasty exhaust fumes and occasional small white cloud), but under boost, the turbo builds to about 5psi, then it practically shuts off. I mean, the car feels like its hit a wall. I've only done this twice, since I dont' want to screw anything up. I know I've still gotta do some logs and possibly install my AFPR thats I've got sitting around, but I'm going overseas tomorrow and I might not have time. So, can anyone give me some suggestions on 1.) HOW to log with a vag-com (what I should be looking for in addition to block 115) 2.) what the hell this CEL means.

My mods are:
T25 Full GT2871r .64 a/r
Chris Tapp program tuned for 630cc injectors and TT225 MAF
3" catless downpipe to Milltek exhaust
NGK BKR 7e plugs
DUH Front mount,
etc etc

**317ssayzarc** · 06-19-2008 04:50 PM

what are you getting for afr's?

**JumboBlack1.8** · 06-19-2008 05:13 PM

Sadly, I'm not even sure how to use Vag-com yet.....just got it...so I dunno how to access the advanced measuring blocks. Any hints?....I just need some brief help with Vag-com so I can provide a bit more information

**JumboBlack1.8** · 06-19-2008 05:17 PM

Measured group 003......My air mass at Idle is 299.72 g/s which sounds really high.....the idle is fluctuating between around 800 and 900rpms

**solowb5** · 06-19-2008 05:20 PM

Does the 01 use fuel cut for a saftey mode? Sounds like your maf is going slowly. From your sig I take it you are an 01. If so unplug the maf, reset the ecu, and see how she runs.

**JumboBlack1.8** · 06-19-2008 05:27 PM

I'll give it a shot once she cools down some.....thanks

However, I've read other threads with guys having somewhat similar problems, but their getting codes for the MAF readings being too low, not high.....when the reading is low, I've read that means the MAF is dying.....but I didn't come across any threads when I searched for this particular code.... i dunno whats up

**317ssayzarc** · 06-19-2008 05:34 PM

regardless, unplug the MAF and get a wideband gauge ASAP (like now)

no setup beyond a k04 should be running around without a afr gauge

**Seerlah** · 06-19-2008 05:35 PM

16487/P0103/000259 - Mass Air Flow (MAF) (G70): Signal too High
Possible Symptoms:
Probably no serious malfunctions
Loss of power
Possible Causes:
Wiring and/or connections (short circuit?)
Mass Air Flow (MAF) (G70) defective
Possible Solutions:
Check wiring and connections
Check / Replace Mass Air Flow (MAF) (G70)

And I thought CTapp has MAFless tunes for the AWM. Correction, they do have MAFless tunes. Do you even need that MAF?

*yes, I am a noob. but I learn

**JumboBlack1.8** · 06-19-2008 05:44 PM

NO, i guess I really don't need this MAF. I could call Tapp and request to get the program reflashed to a MAF-less tune....but I've already done all the intake and intercooler plumbing (which was a SERIOUS bitch), and to undo it now would be another PITA

As far as the wideband gauge goes, it was my plan to pick one up, but my budget for this build is completely depleted, and I'm going to Spain tomorrow for 3 weeks, so I can't spend anymore money on car shit....But as SOON as I get back, its gonna be my first purchase

Any other way to measure AFR?

**solowb5** · 06-19-2008 06:01 PM

DOn't know what block it is on vag but, you can log your o2 readings. Only on the 01 can you do this bc it is a wideband. You have to multiply the values to get the true a/f since it reads in lambada.

**JumboBlack1.8** · 06-19-2008 06:27 PM

I did the 003 block to find the Air mass readings at idle.....my readings are posted above....but an AFR gauge will help me figure out my specific problem when boost kicks in

I tried unplugging the MAF and resetting the ECU and i still get the same issue. Boost cut-off around 3.5k rpms or around 7psi. Then the CEL kicked back on.....Any other suggestions out there for a quick-ish fix?

**biketsai** · 06-19-2008 09:56 PM

are you getting misfires? IS that the right size MAF?

**JumboBlack1.8** · 06-19-2008 10:05 PM

It might not be.....anyone know the exact diameter of a TT225 MAF housing? This one is 3.25"

**Seerlah** · 06-19-2008 10:27 PM

I was under the assumption you are required to use a VR6/Ford Lightning MAF. Just not sure if it is 3" or 4" for the CTapp application. You should give them a call and ask. Or if you want, I can call my dealer tommorow for you and ask what are the requirements.

GT2871r
Now we're talkin serious power. You have pretty much 2 options. The .63/.64 A/R or the .82/.86 A/R. The .63 and .82 are T3 flanged, and the .64 and .86 are T25 flange. T3 flows better. With the .82 you will have more lag, but more topend power. You also will not have to swap out rods. With the .63 you will have much faster spool (20+psi before 4k), but you will have to swap out rods. You will need Tuning, Exhaust Manifold, Custom Intake, VR6/Ford Lightning MAF, 440cc/630cc Injectors, AFPR, MBC/EBC, Exhaust, FMIC, Clutch, New Mounts, and Walbro 255. (new fuel filter at the same time is a good idea).