1996 850 GLT Slow o2 Response

mijo850glt96 · Post by **mijo850glt96** » 25 Feb 2009, 20:39

Recently went to get a code check and it came back with o2 sensor slow response, I want to replace both sensors but i dont know where both are I have an idea of where the downflow one may be. Comment or suggestions?

Post by **MadeInJapan** » 25 Feb 2009, 20:59

You may not need either 02 sensor at all- could be just simply a vacuum leak somwhere that the sensor is responding to. I have 170K miles on my S70 and the rear has never been changed...I changed my front one out at 120K miles for safe measure but didn't really need to back then. The second one (I think this is what you're asking) is right behind the CAT converter on the exhaust.

mijo850glt96 · Post by **mijo850glt96** » 11 Mar 2009, 21:11

well I began to trace vacuum lines and found that the Idle Vacuum Control pump is overheating and no good. So Im going to replace that but the o2 sensor is still top priority