2001 Infinity I30 P0430 Code keeps coming back.

Question

I have a P0430 code on a 2001 infinity i30t. At first I just shut off the code and it didn't come back for about 6 months. Then it cam back so I started using Lucas fuel injector cleaner in my gas and it stayed away for months so I stopped using the additive. Not it cam back and when shut off it cam back in about 30 miles. Yesterday I removed the bank 2 (front) Cat and both O2 sensors. Nothing looks clogged or damaged. I looked at a plug on that side (NGK) it was a nice tan color. I used a propane torch and heated up the two O2 sensors and the pre cat sensor went up to about .95 volts but the after cat sensor went up to 1.25 volts. I don't mind spending the money (too much) on parts but I'm not sure what is causing the problem. Any suggestions before I put it back together or just bit the bullet and order some parts. The car has about 125,000 miles and runs pretty darn good.Thanks,Garygbressler@aol.com

Answer 1

Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem.

Comments

I gave in and ordered both sensors and an Eastern Cat replacement converter.  Since the down stream sensor seems impossible to replace without removing the converter I don't want to remove it again.  I sure hope this helps and I'll update next week when the parts arrive.
Thanks a lot.

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OK, I installed the Eastern Cat replacement and both O2 sensors and have not seen a check engine light since.  I actually believe the car idles better than before.  I had a little trouble with the heat shield they put on the Cat because it gets in the way of the bolts when installing it.  Even harder to get a socket around the nuts to tighten them.  I wrote to eastern to tell then and got a very nice response and they are going to look into modifying the shield.  Very happy so far.