# 2000 Infiniti I30 Cat Converter? Dead or a Bad O2 Sensor? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** catalytic-converters, infiniti, i30\ **Created:** [May 19, 2010, 10:56pm UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088 "2010-05-19T22:56:11Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![sheehanjc](https://avatars.discourse-cdn.com/v4/letter/s/90db22/32.png) [@sheehanjc](https://community.cartalk.com/u/sheehanjc)\ **Post date:** [May 19, 2010, 10:56pm UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088/1 "2010-05-19T22:56:11Z")
The “Service Engine” light is on and the stored code is P0430. 144,000 miles and the front tube and sensors were replaced in a recall three years ago. Before I surrender to the gentle and expensive ministrations of the Infiniti dealer, here is my question: How likely is it that the O2 sensor and not the converter is bad? A new sensor is about $200 and an aftermarket converter is about $300, but neither one is returnable if I replace it myself and guess wrong. Any insights? ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [May 19, 2010, 11:19pm UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088/2 "2010-05-19T23:19:30Z")
An exhaust leak or a bad O2 sensor will trigger this code. Look for an exhaust leak and measure the output from the O2 sensor. You’ll need a service manual to give you the specs. Why would you want to go to the Infinity dealer? Any decent mechanic should be able to diagnose and repair this. ---
**Author:** ![sheehanjc](https://avatars.discourse-cdn.com/v4/letter/s/90db22/32.png) [@sheehanjc](https://community.cartalk.com/u/sheehanjc)\ **Post date:** [May 19, 2010, 11:32pm UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088/3 "2010-05-19T23:32:09Z")
Actually, I wouldn’t go to the dealer. There’s an excellent mechanic nearby. No exhaust leak – checked thoroughly. The electical test requires a dual-input voltmeter, where you count the switching rate of each sensor simultaneously at 2,000 RPM and then calculate the ratio to see if it’s within limits. I may be whistling past the graveyard here – but I just spent $1,400 having my other car fixed and it would be nice if I could do the repair myself. ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [May 20, 2010, 12:08am UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088/4 "2010-05-20T00:08:42Z")
Well, if you can quote the specs, you should be able to do it yourself. Do you have a dual-input voltmeter? Do you have an O2 sensor socket? If not, this is a perfect opportunity to add to your tool collection. ---
**Author:** ![Manolito](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/manolito/32/3070_2.png) [@Manolito](https://community.cartalk.com/u/Manolito)\ **Post date:** [September 13, 2010, 4:43am UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088/5 "2010-09-13T04:43:12Z")
At 144k miles, there is an excellent possibility that the other O2 sensors are getting too slow to satisfy your OBD II control system. I would not trust the verdict of a voltmeter, even a dual input voltmeter, when it comes to identifying an aging O2 sensor. You really need an oscilloscope to see if it is still up to par. A new OEM oxygen sensor for this car is $110 on line with free shipping from any of several reputable sources. If you take it to a shop, whatever the problem turns out to be, you are almost certainly going to end up with a new sensor, so you really have nothing to loose trying it yourself. ---
**Author:** ![sheehanjc](https://avatars.discourse-cdn.com/v4/letter/s/90db22/32.png) [@sheehanjc](https://community.cartalk.com/u/sheehanjc)\ **Post date:** [September 13, 2010, 2:44pm UTC](https://community.cartalk.com/t/2000-infiniti-i30-cat-converter-dead-or-a-bad-o2-sensor/49088/6 "2010-09-13T14:44:59Z")
That’s my thinking as well, especially since the trouble code is intermittent. If I clear the code, sometimes the car will go weeks before it resets, and other times it’s just a few hours. So I’m going to start with the sensor and if that fails, an after-market front cat converter is about $250. Thanks for your advice