Car cutting out at 4k rpm

[looseboost]

Driving my car normally on a straight road about to pass some one so i down shift into 2nd at about 2k rpm it goes up to 3k rpm and it just feels like loose all power.. i keep going it gets to 4k rpm and the car starts cutting out and bucking at 4 rpm so i shift so im at a lower RPM. I drive home and it starts bucking and cutitng out whenever it hitting 2k rpm and the traction control and abs light come on.

i parked the car let it sit for 5 minutes come back out and turn it on now the checkengine light is on and the car sounds like its cutting out and not running right at idle. I dont think i will be able to make it to the audi dealership to get the code read. any ideas or suggestions?>

[RedRocketS4]

vag-com or autozone... maybe your MAF sensor? What year is the car? mods, etc?
try starting the car, then let it run a minute, then unplug the MAF sensor while the car is running... see if it helps.

[The_Jerbel]

VAG the car for sure. Also get under the front of the car and make sure the lower IC hoses are secure. Pressure test the intake system.

[looseboost]

2001.5 90k Miles No mods at all

i wouldent think it would be a boostleak problem because of it feeling choppy at idle. I deff need to read the code but im not to sure if i will be able to make the 10 min drive to the dealership near me.

How would i know if it was a bad MAF sensor wut would it do if unplugged??

[The_Jerbel]

It would do nothing at all...

And yes, it could very well be a boost/vacuum leak...
Also definitely check those IC hoses.

[looseboost]

im having trouble understanding how it could be sumthing with the Pipeings but i will take a look when i get home... if its at idle its not reallly boosting so it would cause a choppy feeling to happen at idle?
thanks for all the help btw

[The_Jerbel]

Because the air intake system isn't only used for boosting, it's also used for vacuum when the engine is running and the turbos aren't making boost. The engine needs a certain amount of vacuum to run (and idle) properly.

[looseboost]

Thank you for clearing htat up when i get home ill tkae a look at the lower IC hoses and the TBB since i do not have a pressuretester

[looseboost]

still have not looked at the car but quick quesiton.
when i replaced the aUx waterpump i did not have clamps to hold the thing vacum line that runs from diverter valve to diverter valve so i just shoved them on.. if that had a small vacum leak from those tiny lines could that be causing it?

[The_Jerbel]

probably not, it would have to be a fairly big leak to cause your car to hunt for idle. You should put some zip ties on those lines either way.

[looseboost]

as far as i can tell all the IC pipeing is on tight the pipeing from the Y pipe is on tight .. all pipeing going to the diverter valves are tight.. i made sure all wires are securely in on the air box..and still its like feeling like its in limp mode or sumthing around 3rpm its just cuts out and jerks... can it be anythign to do with the 02 sensors cuz i hear a wierd sound coming from underneath neerthe DP'S kinda sounds like the driverside turbo which is already blown ....

[The_Jerbel]

Pull the codes with a VAG com.

[looseboost]

Got the Code read and it Read 2 Errors MAF or VAF error and Mulitple misfires..
This could be because of the MAF andidk wut a VAF is??

[The_Jerbel]

Replace the MAF sensor.

[SoEvoL]

you can try to clean it, but i would buy a new one. if you had vag-com you can observe your maf readings, if they dont change then the maf has probally failed or been disconnected and its using a simulated number so the car can get you home or to a dealer. its a failsafe mode programming or limp home strategy i believe.

VAF= Volume Air Flow