2000 S4 tip, chipped(unknown), Level ten tranny and torque converter, magnaflow exhaust.


I experienced total boost loss for a few minutes. I was on the interstate doing 55 and just stepped on it to jump to 85 for the fun of it. I had no boost. got off the interstate and tried a heavy acceleration and no boost again. Within 5 minutes no problem. went driving for 30 minutes really pushing it trying to get the same result and it didn't happen. Anyone got any idea what happened?

 

you might have a fouled sensor. try and run a vag check if you can. my egt sensors were shorted out causing my car to run in limp mode at 5psi. every now and then it would let me run full boost because it was an intermittent short. idk what that means but i just swapped out both my sensors and 400 dollars later they're running full boost. do you have a boost guage? 5psi doesnt feel like the car is getting any boost but it still is. hopefully its that easy of a fix. cept the driver side sensor is a pita to get out. much easier to get back in tho

 

What sensor are you talking about? o2? I am experiencing a problem like this right now. I have a boost gauge but im not getting more than 10psi from my GIACX chipped a6. I was usually settling around 18psi when it ran normally. the other day it wouldn't go past 5psi and the cel came on giving me codes for bank 1 and 2 too rich(o2 sensors i presume). i cleared the codes and boost went back to stock 8-10psi. when i get on it, I can here a loud woosh of air in the engine bay, and its not my airbox. I have 710N Diverter valves and a samco throttle body boot to handle the increased psi. Any ideas?

 

Curious about the resolution as I've been having a similar problem. Was intermittent, but has stayed at max 5 psi for about 4 days now.

04A6RGR - you at 1/75? The location and "RGR" made me ask. I was A. Co 1/75 '92-'95...

 

the sensors i was talkin about were the exhaust gas temperature sensors. K11 that sounds more like you're having the issue i had...04a6 it sounds like you may have a boost leak somewhere else. try inspecting your intercoolor inlet and outlet hoses

 

Don't rule out DV's. I had the same whoosh from the engine bay, especially when shifting. I thought that it had to be something other than the DV's. Nope - turns out that my 710n's only lasted about 6 months on a chipped S4 (around 16 psi). After putting in some Evolution Motorsports DV's all returned to normal.

I was also getting codes related to running too rich when I have failed DV's. The computer is throwing too much fuel becuase it doesn't know that some boost has escaped. Hence, the codes about running rich. Since I upgraded the DV's I haven't had any codes at all, its been about a month.

Sure sounds like DV's to me.

Good luck!