# Post cat O2 sensor question **URL:** \ **Category:** Canada Nissan Automotive\ **Created:** [April 13, 2006, 8:11pm UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209 "2006-04-13T20:11:25Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![imported\_silvia](https://avatars.discourse-cdn.com/v4/letter/i/e79b87/32.png) [@imported\_silvia](https://forums.speedlife.net/u/imported_silvia)\ **Post date:** [April 13, 2006, 8:11pm UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/1 "2006-04-13T20:11:25Z")
well, I went into the exhuast guy that does all my work for me today. I knew it was there but forgot, the O2 sensor in the cat. I was hoping to get rid of the cat and put a resonator in where it is now. So…my question is: can I take out the cat and put the O2 sensor into the exhuast anyway? or will that screw with my air/fuel levels to try and improve emissions? Is there any easy solution or do I need to get a high flow cat or something? I have the cat back, and the elbow, and he is going to make the downpipe. Should I add a flex pipe into the downpipe? Please offer any advice or experience. Thanks all! ---
**Author:** ![Dynamo7](https://avatars.discourse-cdn.com/v4/letter/d/5fc32e/32.png) [@Dynamo7](https://forums.speedlife.net/u/Dynamo7)\ **Post date:** [April 13, 2006, 9:07pm UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/2 "2006-04-13T21:07:25Z")
I’m personnaly goin to put in a high flow cat when i do mine. I like clean air. I’m not positive what the one in the cat does, but i doubt it would hurt anything to put it in the test pipe. I think it just tells the computer when ure cat is up to temp. Maybe unhook it and drive around and see what it does. ---
**Author:** ![jdms13rhd](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@jdms13rhd](https://forums.speedlife.net/u/jdms13rhd)\ **Post date:** [April 14, 2006, 11:36am UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/3 "2006-04-14T11:36:29Z")
you will be fine! What I do is drill a 3/8 hole in whatever I am throwing in there and then grab a hammer and smash the treaded nipple off the factory cat and weld it on whatever I use. Ive even cut off the flanges off the factory CAT and rounded out the middle to 3" with a grinder and welded a pipe between. Costs $6 for a test pipe plus you time to weld them and grind the flanges. Ive pretty much done this on most of our inventory cars we had in Last summer. ---
**Author:** ![CA18DET-180SX](https://avatars.discourse-cdn.com/v4/letter/c/e0b2c6/32.png) [@CA18DET-180SX](https://forums.speedlife.net/u/CA18DET-180SX)\ **Post date:** [April 14, 2006, 1:56pm UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/4 "2006-04-14T13:56:28Z")
all I did was pulled my cat out, knocked the crap out of it and put it back in. I was afraid it was going to sound tinny but luckily it doesn’t. ---
**Author:** ![imported\_silvia](https://avatars.discourse-cdn.com/v4/letter/i/e79b87/32.png) [@imported\_silvia](https://forums.speedlife.net/u/imported_silvia)\ **Post date:** [April 15, 2006, 8:22am UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/5 "2006-04-15T08:22:22Z")
Is it an O2 sensor or just an exhuast temp sensor? ---
**Author:** ![CA18DET-180SX](https://avatars.discourse-cdn.com/v4/letter/c/e0b2c6/32.png) [@CA18DET-180SX](https://forums.speedlife.net/u/CA18DET-180SX)\ **Post date:** [April 15, 2006, 11:37am UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/6 "2006-04-15T11:37:32Z")
When I screwed it outta my cat it didn’t look like a O2 sensor it did look more like an EGT probe than anything. ---
**Author:** ![jdms13rhd](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@jdms13rhd](https://forums.speedlife.net/u/jdms13rhd)\ **Post date:** [April 15, 2006, 3:53pm UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/7 "2006-04-15T15:53:07Z")
agree^^ but unsure really, exactly what it is. ---
**Author:** ![1mns13](https://avatars.discourse-cdn.com/v4/letter/1/8491ac/32.png) [@1mns13](https://forums.speedlife.net/u/1mns13)\ **Post date:** [April 15, 2006, 10:01pm UTC](https://forums.speedlife.net/t/post-cat-o2-sensor-question/142209/8 "2006-04-15T22:01:38Z")
> [@silvia](#): > > Is it an O2 sensor or just an exhuast temp sensor? On a JDM car it’s supposed to be exhaust temp.