Engine Knowck Seonsor Low Voltage
 

hey guys, i'm just wondering if the Engine Knock Sensor Low Voltage can be an easy fix? i just got back from the dealer and they want like $1000 to fix the engine knock and the rear 02 sensor. i had problem to get the car start at times. Somestimes i had to crank it like 5 times to get it start. It is kindof ridiculous because i brought the car the dealer with the same problem and they replaced the engine. But like 5 months after, i'm getting the same problem again. and this time they said that's it not under warranty to fix these 2 problems. Can you guys gime me some thought? Thanks

anyone?