Boost pressure sensor was the problem!

[S4evr]

So for months now, I have had this problem. If i slammed the gas to the floor, the car would shutter and bog for a second, then it would pick up and go. BUT, if i pushed the gas to the floor a little slower, let the rpms build up, THEN i could punch it and it would go fine.

Idled fine, 20vac, WOT was fine, a solid 21psi. only other problem i would see is that the boost would creep up unless I floored it, and the car ran very rich (backfired a shit ton)

I did some basic trouble shooting and realized at WOT, the fuel and ignition is controlled by the ecu mapping which would explain why the car pulled normally at WOT. THEN, since partial throttle driving is controlled by various sensors like the MAF, and MAP(boost pressure sensor on the TBB) i realized it had to be sensor related. narrowed it down to the boost pressure sensor, replaced it, and I'm back up and running!

Feels great to be back lol

[DannyDeez]

Where did u get the sensor, how much was it and how hard was the install? Glad ur car is running good again!

[mholme]

Where did u get the sensor, how much was it and how hard was the install?

The MAP sensor like he said sits on top of the throttle body. Not hard to install at all. Unfortunately, it's not that cheap either @125 bucks or so...

[S4evr]

brookline audi quoted me $233 for it, but got it from a local shop for $120

[DannyDeez]

Thanks. Does anyone know where to get it or a part #? I cant find it listed for the S4 anywhere.

[mholme]

Does anyone know where to get it or a part #? I cant find it listed for the S4 anywhere.

078906051.

[DannyDeez]

Sweet thanks for helping my laziness! I know I could have just pulled the plastic cover over the TBB and found it.

[S4evr]

078906051.

that is the correct part number, however my shop could not find it. we ordered one that looks exactly the same, just a slightly different part number. I will post later which one i got

[DannyDeez]

that is the correct part number, however my shop could not find it. we ordered one that looks exactly the same, just a slightly different part number. I will post later which one i got

Any update on which one you got?

[mholme]

Maybe it was the Bosch part# he got, unless it was a chinese knock off. I'm fairly sure that sensor is not shared with any other engine besides the 2.7T and 078906051 is the part number.

[RolledMySTi]

Good to hear you solved the problem. Sounds like one of those that will drive you mad.

[haus4]

Its about time you figured it out. Im glad you got it and are enjoying it now.