i taken the to advance auto parts and put the comp on it he told me is the oxgen sesor is bad need to replace all four do the car has four or one
my car has a check engine light on on 2003 Ford Escape
It probably has 4. I wouldnt think all are bad. I know that is around $100. Does the code not list (Upstream or Downstream) or (Bank 1 or Bank 2) in the code. If not and you need to save, you can just get a sensor and switch it out until the code is fixed. It just takes more elbow grease. Without a scanner that can give you a serial data list that is about the only way to figure it out. the data list will give you actual readings from each sensor telling you which is bad. If you try this you will want to clear the codes after each switch. You can do this by disconnecting both battery terminals. Then hold them together for 30 seconds. Reconnect and drive. if the light comes on then its time to switch. Something else to consider is something wrong around the engine can cause an improper mix of air and fuel. This would alter the exhaust that the sensor meters. The sensor could just be telling you that it is reading a bad mix. With that I would thin you would have other codes. Just something to consider should a new O2 sensor not fix the problem.
THE CAR DOES HAVE 4 O2SENSOR BUT YOU ONLY NEED TO REPLCE THE BAD ONE. HOW TO NOW WICH ONE IS BAD THE COMPUTER TELLS YOU SO YOU SHOUD ALLWAYS ASK FOR THE NUMBER THAT THE COMP GAVE IF THAY DO NOT GIVE YOU THE NUMBER CHANG GRAGE