How do you replace oxygen sensor for Chevy Venture?

Answer 1

Drop the engine basket. It takes an 18mm wrench. Loosen one bolt all the way, thread it back in 4 turns. Loosen the other one to the same length of bolt. Don't take both out at the same time, the engine will fall if not supported. Leave the front two in place and the engine basket will drop about an inch. That's enough to get to the upstream o2 sensor near the manifold. Un-clip the sensor from its connector, there's a keeper clip holding it together. Sometimes you have to splice a new connector on. Match the wires, and crimp. Solder doesnt stick to the high temp wire. Get an oxy-propane torch and heat exhaust pipe till it gets red. Some people just run the engine a few minutes, but that doesn's always get it hot enough to break it free. Loosen the o2 sensor. It's hard. Get the specialty wrench from the parts store. I used a 7/8 wrench and bent the box end to a new angle to fit the area, ground the box end a little with an angle grinder, cause the exhaust manifold gets in the way, and it worked. A deep socket might work, too, if you cut the wires. You can get a 1/6 turn and that's enough. Very tough. A good work light helps. Make sure the new o2 has some glass pack thread anti seize on it, or it won't come out easy in the future. The downstream sensor is easier because it is on the lower end of the muffler and you can reach it easier. Before the o2, clean the MAF sensor with special cleaner and check the IAC valve. I