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I've owned this car about 3 months now. I've had the SES light come on 3 times. The first code I can't recall but I think it was PO430. I checked around and it was usually indicative of a bad bank 2 catalyst. I replaced the bank 2 cat and the SES light went out. The next time the SES light came on the code was for Bank 1 Sensor 2. I replaced that sensor and the code went away. Last night the SES came on and the code is P0420 catalyst system efficiency below threshold. Bad B1 cat or bad o2 sensor. This is weird. Fix one and the next one goes bad. It's an old car w/ mostly original parts so I'm going to try the o2 sensor first. That bank 1 precat is pricey so thats a last resort. The really odd thing is the car runs great, still has good power, and gets good gas mileage. The dealer service advisor who drove the car into the service area for the airbag recall on Monday even commented on how well the car runs.
After I made that post I remembered reading something about only Cali cars having 4 o2 sensors. Mine has 4 o2 sensors. I suppose if this is a CA spec car I'm going to have to use CA spec cats or else the ECU is always going to be thinking there is a problem. That make sense?
Forget the cats entirely, just throw some o2 sensor spacers on there and be done. As long as your sensors work, youll be ok. You could do away with the cats entirely even. However worth noting if your precats are old either bore them out or replace them, or else they will eventually break apart and your motor will ingest a bunch of chunks of metal and ceramic. But yeah just buy a spacer for a couple of bucks and call it a day, tricks the sensor into thinking the cat is working just fine by removing the sensor from direct exhaust flow so it detects less emission particles.
nice find, additionally amazon may have similar or better pricing for bosch O2 sensors, i just got both downstreams from them both around 52 - 57 dollars depending on wire length (diff part , diff length/location, diff price)
something is telling me the 2000 - 2001 is a little bit different for the downstreams, but it could just be the y-pipe and not the sensors, i forget, its def posted around here.
IIRC 2002-2003 is same across the board IIRC cali or fed
Yes it is a good find but it doesn't fit my car. But it makes me tend to believe what I read about Bosch making the OEM sensors. I used Bosch on 300zx cars but I tried one on my Acura and it didn't work out. I thought Denso and NGK made all the Japanese OEM sensors. I'm guessing the Y pipe is the whole bank 1 precat to main cat assembly?
I need to find my emissions sticker and see if my car is epa or cali. The y pipe assy's look the same for both specs in pics but have different part numbers.
Look at the outlet end of the main catalytic converter (beneath the passenger seat). Look from the driver's side and if you see an O2 sensor, you have a Fed spec car. No O2 sensor means you have a Cali car.
Last edited by DennisMik; Jan 11, 2019 at 01:18 PM.
