How To Replace Rear Oxygen Sensor On Chevy Venture Van

Question:
Is the rear o2 sensor something I should try to tackle? It is my understanding that theres 2 different o2 sensors one before the catalytic converter and one after. Is there any easy way to determine which one is malfunctioning without putting it on diagnostics? It seems to run fine when driving but does idle rough when parked.

Was also told that by taking out the main two bolts on the front of the engine that it would come forward enough to get to the o2 sensor this leads me to believe it is the one before the CAT????? Please Help Me!! 1997 Chevy Venture. 3.4L 6cyl. Check engine codes = possible o2 sensor. Repairs done prior = previous owner stated that it need an o2 sensor.

Answer:
It does sound like they were talking about the oxygen sensor in the rear exhaust manifold, which is the pre-catalyst sensor. Removing the 2 front upper engine mount bolts will give room in the rear to access that sensor, with the proper tools. As long as the van is in park, and you 'slave' the motor forward, then secure it to access the rear exhaust manifold.

That sensor is below the ignition coils/module assembly. To help decide if that is the sensor, you could have a scan done. Most of the large national parts store chains will do this free of charge. That may be the cause of an idle problem, but it may also be the result of another problem. I Would suggest getting the scan done first. Let me know if you need more help.

Question:
I am going to change the Catalytic converter on my 1997 Chevrolet Venture Van. I am worried about removing the sensor without breaking it. Any suggestions? Thanks.

Answer:
Hello and welcome Jose, Sargent first class. Thank you for your service to our country. Assuming your are referring to the oxygen sensor, the best way to get those out is to soak the sensor at the mounting point with a rust breaking lubricant. Let it sit for awhile, then use your wrench to remove.

It will be tight, but once you break it loose, it will come out smoothly. If it cannot be removed while the exhaust is still attached and in the car, the remove exhaust, put it on the floor, step on the pipe, and use plain old muscle to remove sensor.

If all else fails, a torch is always a good tool to heat it up enough to remove it. If you do break the sensor, that is not a big problem, since the O2 is not very expensive. Once again, thank you for your service.I have answered a few question from military personnel in the past year, and makes me very happy and proud to offer some help.