Thank you for the reply,I just change the transmission fluid,I bought it from Nissan, I replaced the spark plugs, ignition coil and distributor cap and also the air filter. I haven't replace the fuel filter and check the fuel injection. Can you advice me also, when sudden press of gas pedal, there is a sound coming from behind sounds like " tog" as if I am pulling something. Sorry for this stupid question, do ineed to replace the oil in the differential? Again thank you waiting for your reply. And somebody has some insights too will be appreciated.