AUDIos my migos

So I have been having this problem for quite some time my car has a red battery light shown in picture and from everywhere I've read that means bad alternator. Well I got a new battery and a new alternator and it went away for a while, well now it's back and idk wtf to do. I've been having weird power loss in a little over half throttle and it just cuts out like I lost all my boost and I hit the brakes or something. But it still keeps going. It's been giving me so many weird bull**** problems and I can't keep dumping money into it to see what the issue is. SOMEONE PLEASE HELP. I'll post a pic here soon my phone is not allowing it for some reason

plat27265

Do you have VCDS or some other scan tool to find out what the error code that is causing the red battery icon to light up? You need to be dig a little deeper and narrow down the possibilities before running around and changing parts.

AUDIos my migos

I've done the scanning the only codes that pop up is a p0141 and p0420 and it says I need a new MAF but that can't be solving the issue with that. And I replaced an o2sensor thinking that at the first time because it said running too lean. But idk dude ****s been bugging the hell out of me.

Walpole5

Have you checked the voltage at the battery with the car on and off? Off, it should be a little over 12V. On, it should be around 14.5V. If you got a rebuilt alternator, it could be bad. It's happened to me.

AUDIos my migos

I have and everything came back positive, that's what really threw me off. And the other day the light hasn't came back on. Idk what tf is up.

Antione Crawford

At least you have simple problems lol. Thank your lucky stars you don't have an abundance of leaks which lead to smoke which is what myself and MANY other Audi owners experience (mostly due to timing case rtv deterioration or valve cover gaskets.

But if your problems and same codes come back, here's two easy fixes for them:

P0141 = A faulty after cat sensor on your passenger side (Replace the o2 sensor and the code will clear)

P0420 = Catalytic malfunction mostly due to clogged passages. This can be cleared up by pouring in 1 gallon of lacquer thinner (fast drying) in your gas tank. ONLY do this when you have roughly half a tank of gas so it will dilute the thinner. If you do it with barely any gas, you run the risk of ruining seals or gaskets. Half tank of gas dilution eliminates this worry and will clear out the catalytic converter to near brand new if you drive it for roughly an hour on the freeway after doing so. My father has been doing this at his shop for 40 years and never ruined a car once with it.
The alternative to this is removing your cat converter and cleaning it out with laundry detergent and water. Or you can just replace it which usually costs usually $1000+.