Car starts "slipping" after driving for a while and one of the fans doesn't work ..

CEL/SES light read the P0720 code as well as P0420(bank 1) & P0430(bank 2)

which sensor do I need to replace?

autozone CEL/SES receipt says "vehicle speed sensor" but I have also found the "existence" of transmission revolution sensor

any website suggestions for purchase other than local stores and dealer?

Here's troubleshooting for the P0720 code: http://www.nicoclub.com/FSM/i30/2001/at.pdf (page AT-114)

Here's troubleshooting for the P0420/P0430 codes: http://www.nicoclub.com/FSM/i30/2001/ec.pdf (start at page EC-357). It should walk you through determining which O2 sensor(s) are needed.

You can pay a premium and get them at the dealer or you can order Bosch (non-generic) or Denso branded O2 sensors. I hear those both work well.

thank you! I want to take care of P0720 first and the go from there. do I need vehicle speed sensor or transmission revolution one?

It seems to be the revolution sensor. Says you can't test it with a circuit tester, only Consult.

Here's some pix I believe that will help: http://picasaweb.google.com/cefiro.calsonic/P0720VSS

audtatious wrote:It seems to be the revolution sensor. Says you can't test it with a circuit tester, only Consult.

Here's some pix I believe that will help: http://picasaweb.google.com/cefiro.calsonic/P0720VSS

thank you so much! I found some websites that are selling them for ~$70 when autozone goes for $150.. any suggestions on that? I will be ordering it with the radiator fan panels just to save on shipping and what not

As I'm helping you I would not be doing you any favors by NOT suggesting a Nissan OEM part as you are ensured it will work. With that being said I usually don't have an issue using a non-OEM part, hopefully from some manufacturer I've heard of.

audtatious wrote:As I'm helping you I would not be doing you any favors by NOT suggesting a Nissan OEM part as you are ensured it will work. With that being said I usually don't have an issue using a non-OEM part, hopefully from some manufacturer I've heard of.

well said, going with the nissan oem. what can I do about the P0420?

Those are O2 sensors. I would replace them in pairs if possible.

audtatious wrote:Those are O2 sensors. I would replace them in pairs if possible.

I thought P0420 and P0430 alone meant that there's no problem with O2 sensor (because then I would have had other codes in addition)

Further looking it may not be the O2 sensors, may be a number of things

- Three way catalyst converter Bank 1
- Exhaust tube
- Intake air leaks
- Fuel injectors may be faulty
- Fuel injector leaks
- Spark plugs may be faulty
- Improper ignition timing
- Engine Control Module (ECM)

Here is a 2000 Maxima TSB concerning the problem: http://engine-codes.com/uploads/nissan/NTB00-070b.pdf

your 2000 I30 probably has a similar TSB as the I30 and Maxima are pretty much the same car.

audtatious wrote:Further looking it may not be the O2 sensors, may be a number of things

- Three way catalyst converter Bank 1
- Exhaust tube
- Intake air leaks
- Fuel injectors may be faulty
- Fuel injector leaks
- Spark plugs may be faulty
- Improper ignition timing
- Engine Control Module (ECM)

Here is a 2000 Maxima TSB concerning the problem: http://engine-codes.com/uploads/nissan/NTB00-070b.pdf

your 2000 I30 probably has a similar TSB as the I30 and Maxima are pretty much the same car.

really not trying to do a "worthless" fix so I guess I'll have to bring it to my guys when I'm taking care of the oil leak.. A lot of people are talking about resetting a system of a kind? Would that help at all?

The TSB is valid for your car and would not have been posted if it were not quite a common occurrence. I also suggest following through all the steps in the FSM for those errors in tracking down the problem.

I'm not sure about a reset unless you are talking the ECU