I currently don't have the second O2 Sensor in my 96 Civic and it's pulling a check engine light. I've been told that this is the reason that my car idles funny and get crappy gas milage. When I went to advanced wuto parts there were two different oxygen sensors and I didn't know which one to get so I thought I'd ask. Is it the $60 or the $150?

 

thats deff. your problem, either ask for secondary or downstream i believe. Or just get them to pull the code for reference.

 

You don't have the down stream O2 sensor or it doesn't work???

Go back to the auto parts store and ask them for the down steam or after cat O2 sensor like z6hatchboy said.

As for the price question, are you talking different brand prices or primary and secondary O2 sensor price differences?

 

that was just the prices for the primary o2 sensors. I actually dont have it right now, there's just a bolt in the hole.

 

thet are a lot cheaper from here sparkplugs.com , you don't want something that you will have to splice. code for 2nd O2 shouldn't make it run bad, just throw a code, the primary will affect how it runs

gl

 

2nd 02 sensor does not affect the motor in any way at all. It is strictly for reading emmisions for state inspection, and monitoring the catalytic converters effectivness. Bad gasmileage may be due to a worn primary 02 sensor.

 

ah I beg to differ, I had no 2nd O2 in my 00Si and after installing a J pipe to get the code off it ran alot better. I actually didn't think it ran any different either until after I able to get the CEL off.