MendezA5

I have an A5 2010 3.2 v6 getting P21A0 code. Can anyone help me. Has anyone gotten this code before and how did you fix it

P2140

jschrauwen

This just happened out of the blue?
No other work/maintenance done recently?


BTW, never title a thread with "Help" or "Please Help". Most will simply disregard it as most will assume you were too lazy to give a brief description in the title.

MendezA5

Thanks for the info. No other maintainance done. I drove the car from Los Ángeles and back the same day. Installed k&n filter about a month ago. Just order new Bosch plugs for it. Car has about 85000 miles on it

jschrauwen

"And back"? Don't know what this means. Was it a long trip as you haven't mentioned where back (home) is.




Pre-oiled K&N that has the threaded Audi mounting studs to attach in the oem airbox?
Do you not have the service histories from the previous owner(s)?
Are you using 91 octane (or better) with zero ethanol content?
What driving, performance, handling or idling issues are concurrent with this code coming up?
What has been the past type of use? IE: City/urban driving, country driving, highway driving?

jschrauwen

Have you tried clearing the code and seeing if it returns again?

https://www.audiworld.com/forums/q5-...-here-2892555/

OBDII diagnostics. Trouble code definition for code P21A0. Causes of error P21A0

Not finding much info on that code. There should be another (perhaps 4 digit) code that it's connected/linked to when you retrieved it?

MendezA5

Yes I cleared the code and it comes back like around 200 miles. Next time I'll check the scanner if it has another code.

jschrauwen

Answering the questions I asked in the preceding post might help.

MendezA5

Sorry about that. I thought I posted it. I don't have the service from previous owners. I only used 91 from chevron or 76. I live in Los Ángeles so it was like a 560 mile round trip. I filled up in baker Ca. A small town, I'm thinking their gas was either old or they put cheap gas in their 91. I'm thinking maybe it's time To change my plugs. Should received them next week. I also put a fuel injection additive for carbon build up.

jschrauwen

1. There's an app you can use that gives locations in your area for ethanol free gas.
https://www.pure-gas.org/index.jsp?stateprov=CA

2. Please read up on FSI engines and the effects of carbon build up on them. This is a condition for all FSI engines, Audi, BMW, Toyota, etc etc.
Fuel injection cleaner does nothing to remove/reduce carbon build-up on FSI (direct injected) engines as it occurs in the intake track of the plenum and in/around/on the stems and backs of the intake valves. Look on youtube for Carbon Cleaning for Audi's. Only real cleaning is through media blasting (soda or walnut shells) or manual/hand cleaning using solvents.

MendezA5

Thanks jschrauwen for all the info. You think carbon build up can only affect one cylinder. From the info you gave me and i was able to find seems like it could be bad plug, bad coil , or carbon build up. I guess I'll start with the plugs first then the coils. I also tried the Italian tune up.