I have a 2000 A4 1.8T Quattro with 108K and tiptronic transmission. The car shifts into 2nd and 3rd gear without any problem around 2.5K rpm but it shifts into 4th and 5th after 4K rpm. Vagcom does not give any error codes for transmission (it only give P1136-System too lean) Acceleration is terrible for some reason.
Do you think my transmission is dying? Would ATF flush help? Can the problem be related with the P1136 code (probably a vacuum leak)?
Thanks a lot!