Hello to everyone. Need help. I have tls 2001. 24000 miles on it. No power comader. Stock exoust. Have problem with upper cilinder. The thing is that till 3500 rpm it,s mainly not working(only time to time) and starts to work only after 3500rpm. Tryed to change computer, injectors, ignition coil -nothing helped. Compretion seams good. Any ideas wht can be wrong?