LT1_King

hey guys i have a 94Z A4 with Cat delte and LM1. ever since i deleted my cat the car feels real weak for some reason. down low it doesn't feel as strong as what it used to. could this be to false knock due to the loudness of the exhaust? need help ASAP.

shoebox

My personal opinion is that exhaust noise does not cause knock detection. The only way to prove your problem is to monitor it with a scanner.

LT1_King

has this ever been proven?

Kevin Blown 95 TA

It only looks for certain frequencies at certain times or else it would be overwhelmed by all the noises. Banging parts or some types of engine noise can cause it, but like he said, you need to scan it. I don't have a cat right now and my car is probably louder than yours and it doesn't have any knock except for a blip at shifts, where it's supposed to be. And I made my knock sensing MORE sensitive to protect my engine. Make sure you have good gas and get some form of knock detection - no one can answer this on the internet for you.