ok so heres my issues. 99 a4. car was throwing the maf code. car would not shift great unless in trip t mode and a some stuttering and what not. so i replaced it. car started shifting great and then wack. car would stuggle to maintain rpms and would drop from 1k to 100 and back and forth then die. check lights not coming on. i replaced these 2 times and they were both new and alot of $. as soon as i unplug the sensor the rpms are normal and doest die, but has low power and doesnt shift so great. and when i plug it in it dies. or starts acting up again. i clean the throttle bodies as well and sprayed connectors and cleaned and sprayed the sensor. why is it doing this? any help would be great