Pre catalyst woes

[alphatarget1]

I'm pretty sure the precat is bad. Changed downstream O2 sensor, P0430 is still there. The vehicle I diagnosed was in CA. Since most vendors don't ship non-CA cats to CA, I wonder if it's illegal for me to buy a cat out of state and ship it into CA?

 

[SearchMaster]

Illegal? Probably. Do you care?

However, I believe there are two different ECMs for most cars (there were for my Maxima when I thought I was having an ECM problem), so if you have a CA ECM it could possibly have issues with the readout from the non-CA cat. I suspect there's not really a difference - what is the car? If it's a 50-state car there wouldn't be any difference anyway other than SKU, would there?

 

[alphatarget1]

i'm more worried about the smog shop failing us on visual. I have never seen them look under the car to see if the car has a carb cat, though. i'm sure the car will pass smog as is, but the light is really annoying. It's a nissan maxima. I really doubt carb acts are that much more efficient compared to normal cats. California is run by environmental nazis.

 

[NutBucket]

The car won't pass smog with the CEL on, period. And most shops don't really do any inspection to see if you've got the proper cats or even the proper number of cats.

What year is the car? IIRC if it's over 10 years you can "legally" use aftermarket cats. That said, functionally it doesn't make a damn bit of difference whether you use an OEM cat.

 

[ayabe]

Does your car have a secondary air pump system? I had that code on my WRX and it was "secondary air pump stuck on". The system had gotten moisture in it and was totally shot.

 

[SearchMaster]

I'll assume this is a 5G Maxima? I believe P0430 is the problem I had on my '00 Maxima for several years.

Is everything running properly otherwise? I'm under the belief that P0420 often trips even if there's not a problem, my mechanic said that gen of Maxima is "overly sensitive" or something like that.

http://maxima.theowensfamily.com/tsb/NTB00-070a.pdf - here's a TSB that I believe desribes reprogramming the ECM for this type of issue.

 

[alphatarget1]

It's a 2000 infiniti i30. We spent 80 bucks at the dealership to have them tell us that we have the latest ECM software. Code is P0430.

 

[brblx]

i don't know why you replaced the O2. catalyst efficiency codes get set because the rear O2 is switching too fast (on a graph, upstream o2 will produce a waveform that switches constantly, downstream should have a [relatively] flat line.) bad o2's tend to quit generating the proper voltage- they don't start working extra hard because they're bad (and by 'working' i mean generating voltage based on the presence of oxygen). typically either they become unresponsive or the heating element gets burned up.

make sure you don't have any exhaust or vacuum leaks. anything that can cause the presence of extra oxygen in the exhaust could concievably set that code.

as far as CA vs non-CA cats: no idea. but unless california does really weird inspections, they probably just stick a mirror under the car and make sure the exhaust looks factory and the cat(s) are present. as long as you haven't welded in a universal cat or something, i doubt any red flags are gonna go off with a non-CA drop-in replacement.

someone mentioned ECM's. that would be my only concern- that your ECM calibration is specifically for CA smog parts. i doubt a higher flowing cat would cause any issues, but it may be worth mentioning, especially since someone did say they'd had experience with maximas being overly sensitive to catalyst eff codes (i30 = maxima).

 

[EightySix Four]

There are cats online which are CARB certified if you're that concerned about it.

 

[brblx]

can you weld in a 'CARB' cat? i was thinking pretty much any exhaust mod was a no-no in CA.

 

[alphatarget1]

i don't know why you replaced the O2. catalyst efficiency codes get set because the rear O2 is switching too fast (on a graph, upstream o2 will produce a waveform that switches constantly, downstream should have a [relatively] flat line.) bad o2's tend to quit generating the proper voltage- they don't start working extra hard because they're bad (and by 'working' i mean generating voltage based on the presence of oxygen). typically either they become unresponsive or the heating element gets burned up.

make sure you don't have any exhaust or vacuum leaks. anything that can cause the presence of extra oxygen in the exhaust could concievably set that code.

as far as CA vs non-CA cats: no idea. but unless california does really weird inspections, they probably just stick a mirror under the car and make sure the exhaust looks factory and the cat(s) are present. as long as you haven't welded in a universal cat or something, i doubt any red flags are gonna go off with a non-CA drop-in replacement.

someone mentioned ECM's. that would be my only concern- that your ECM calibration is specifically for CA smog parts. i doubt a higher flowing cat would cause any issues, but it may be worth mentioning, especially since someone did say they'd had experience with maximas being overly sensitive to catalyst eff codes (i30 = maxima).

Yeah, I did a bit more research and I should've done more homework before replacing the sensor. I figured the sensor isn't horribly expensive and worth a try. I'll check the waveforms next time to see if it's really the cat. I don't think there are any exhaust leaks at all, so if anything it's got to be the cat.

Smog isn't due for another 1.5 years. woohoo!

 

[5150MyU]

Things that cause a P0430 on your year Infiniti.
3 way Cat.
Intake (vacuum leak) anything after the MAF sensor.
Exhaust leak.
Bad plug (misfire).
Leaking injector.
Ign. timing.
I would say your Cat. is junk-But what do I know.

 

[sontakke]

O2. sensor. extension. ebay.