so a few weeks back my chipped 99 a4 started only boosting to around 3.5-4 psi where as it would usually boost to around 15-16. i figured it was in limp mode and tried disconnecting the battery for half an hour and then driving it. it didnt help at all. i also regularly fill it with 93. this is about the third time this has happened since ive chipped the car, but it usually goes away after a couple days. is there any other methods to fix this besides clearing codes? i dont have access to a VAG so its probably not an option

 

Have autozone clear the codes for you for free.

Have you checked for boost leaks? Have you upgraded your diverter valve?

 

diverter valve is baileys and boost leaks were never an issue...and there are no CELs coming up. will autozone still clear codes if that is the case?

 

Yes, there are lots of soft codes that will be stored without tripping a CEL.

 

Yes, but he disconnected the battery for a half hour, doesnt that clear all the stored codes as well? I was under the impression it did, at least on my b5.

 

does anyone know if the above is true?

 

They have an OBDII scanner that can erase codes. This take you out of Limp mode.

Now do you accelorate hard on the pedal do you notice any issues? Surging? Consider getting sparkplugs. Also you may have a boost leak since 3-4psi isn't much. 15psi is alot and can cause issues.