Stumped - S4 Turns off while driving

[torquewrench]

After having both my catalytic converters replaced, I went to pick up the vehicle. I haven't had it in over a month, so I was elated...for about a 1/2 mile when the car just shut off. No warning lights, nothing. It's as if someone reached over and turned off the key. Still had all lights, etc. Attempting to restart it, the engine would begin to turn over for a fraction of second then stop. Below is a video of the no start condition. Almost like a battery was too low to crank. Jump starting failed. Towed back to shop.
Shop inspected to see if they missed something during cat install. Scanned codes:

P154500 - Throttle valve control system Malfunction
P157900- Throttle valve control module, J338, Adaptation not initiated
P10A700 - Adaptation regulating flap for intake air soiled

Replaced battery with new one since the old was original. Inspected throttle body, and it moves freely. Removed supercharger belt to make sure supercharger would turn freely. The car eventually just decided to start, but it would stall immediately every time right after startup. Adapted throttle body, and the car did start and run seemingly ok. Test drove it around nearby for 10 minutes or so to make sure it would be ok. Left for the 45 mile drive home. 1/2 way home it died on the freeway. Same thing all over again: car would turn over slowly and not start (almost dead battery like symptoms) After waiting for 30 minutes or so, it did start but ran rough. This time a warning came up about the oil pressure being low! Arg. Towed to another shop as I was hoping to get the car closer to my home.

Scanned again:
P154500 - Throttle valve controller malfunction.
P10A400 - Intake Air regulating Flap - Mechanical Malfunction
P164D00 - Oil Pressure switch for reduced oil pressure

Towed car back to shop that did cats. They are investigating it currently. Any ideas?

Stock 2011 Audi S4, ~68K miles.



https://www.youtube.com/embed/RWBRt4mBzxg

[silverf0x]

I don't know if that could help but maybe more info on Year? Mileage? Mods?

[torquewrench]

I don't know if that could help but maybe more info on Year? Mileage? Mods?

Added to post, thanks.

[withENEMYin]

Maybe I am reading it wrong, but was it running fine prior to replacing the catalytic converters?

[RudyH]

I believe there is a valve / sensor that is under the supercharger that needs replacing. I looked through my paperwork and I guess they didn't record the exact code but it was a $20 part but the labor involved was high because it involved removing the supercharger.

I had the same symptoms, and the mechanic cleared the codes. It happened again after, so I cleared it again with VAG on a Friday night. Come Monday the car was driving fine all weekend, gave it a few days and about a year later it never happened again.

[torquewrench]

Maybe I am reading it wrong, but was it running fine prior to replacing the catalytic converters?

No, it had a really bad misfire due to the fully blocked cat. It was running so rough it would barely stay running. Right after the cats were replaced, it ran perfect. Until it didn't run at all.

[BlownOne]

The throttle body code is for throttle position sensor wire harness not being properly connected to the throttle body or there's a short in it. I would not take the car anywhere else (even tho I would want to) because you're going to have to pay a new shop to fix the first shops mistakes. Good luck brotha

[torquewrench]

I believe there is a valve / sensor that is under the supercharger that needs replacing. I looked through my paperwork and I guess they didn't record the exact code but it was a $20 part but the labor involved was high because it involved removing the supercharger.

I had the same symptoms, and the mechanic cleared the codes. It happened again after, so I cleared it again with VAG on a Friday night. Come Monday the car was driving fine all weekend, gave it a few days and about a year later it never happened again.

RudyH- Thank you so much for the info. No one has been able to give any insight, so I appreciate the help!

[BlownOne]

Also the low oil pressure is probably from the rough hunting idle, but hopefully you have a dipstick to atleast verify capacity.

[torquewrench]

The throttle body code is for throttle position sensor wire harness not being properly connected to the throttle body or there's a short in it. I would not take the car anywhere else (even tho I would want to) because you're going to have to pay a new shop to fix the first shops mistakes. Good luck brotha

Thank you sir!

[LocoLobo]

Any updates on this issue?

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[torquewrench]

After months, the problem was fixed simply by replacing the engine. No one knows what was specifically wrong with the engine other than it took an abnormal amount of torque to manually turn the engine. After repair, everything was perfect, however there is no way I was taking a chance of something else going wrong. So, I sold it before I lost my mind. I'm driving a newer Honda CRV. 0-60 in 10 minutes or so. It's painful.

[USAF_Danny]

After months, the problem was fixed simply by replacing the engine. No one knows what was specifically wrong with the engine other than it took an abnormal amount of torque to manually turn the engine. After repair, everything was perfect, however there is no way I was taking a chance of something else going wrong. So, I sold it before I lost my mind. I'm driving a newer Honda CRV. 0-60 in 10 minutes or so. It's painful.

Painful but safe now. I would have done the same if I went through all of that trouble. Thinking of selling mine because of the headaches I've had.


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[LocoLobo]

Ouch, yeah.... My issue isn't exactly the same as yours, hopefully mine won't won't come to that.

[AKPS4]

Wow new engine? Under warranty?

[Gkit19986]

my car shut off today as I as putting e85 while pumping the gas. it took a few cranks to start back up. Im not sure what it could be, Il scan it once I get home and see what codes it gives.