Fuel trim issues and flat spot...MAF?

[savio_v6]

Hi all, basically the car at idle 90% of the time is taking away fuel, upto -11%. When normal accelerating it is adding fuel say less than 12% and on WOT at 5000rpm+ the fuel trims add 20-25% and i experience a flat spot or two.

Please tell me i need a new MAF? The reason i think otherwise is on Dash Command the MAF g/s looks normal, increasing with RPM.
I took it for a drive yesterday with the MAF unplugged and i don't think it made a difference to drivability.

Car is a 2006 2.0tfsi BWA 54,000miles with intake/exhaust mods and a stage 1 remap.

Thanks for help in advance.

 

[Rick @ Unicorn Motor Dev.]

Fuel Pressure is dropping most likely, and it's running lean. You need to log fuel pressure which you need VCDS for.

Rick

 

[savio_v6]

Thanks for your reply mate.

Im still confused as it doesn't explain the rich running while idle. Forgot to mention sometimes the idle feels lumpy but the rpm needle doesn't move.

What else can i check? Dash command tells me fuel rail pressure.

 

[RedDejavu]

put standard air box in and report back

 

[savio_v6]

The k&n typhoon intake has only been on about two weeks. Had standard airbox before but a pipercross filter

 

[RedDejavu]

k&n typhoon known from not performing very well in terms of keeping low fuel trims. Otherwise it might be fuel pump not holding enough pressure. Best is to put car back to stock from and start from there.

 

[Rick @ Unicorn Motor Dev.]

Any intake setup will upset the MAF readings due to turbulence. If you can log fuel pressure then do that.