Bad O2 sensor?

[1bad65]

I threw a P0430 code last night and think I may have a bad rear O2 sensor. Is there any way to test them to confirm they are bad?

 

[SteveP]

to test them, pull it out and put a new one in.

 

[reefblue93]

to test them, pull it out and put a new one in.

That's the long way of saying "no".....

 

[lito]

Why the sensor and not the cat?

Never mind, just saw you have "high flow" cats, a tune will resolve that.

But still, why the sensor would be bad?

 

[SteveP]

P0430- Catalyst System Efficiency Below Threshold (Bank 2)

means that the 02 sensor is not reading the cat. This usually happens when a 02 goes bad. If it was your cats, it would buck when accelerating.

Only way to check the cats is pull them off and see if it looks like someone dropped a frag grenade in it.

 

[lito]

P0430- Catalyst System Efficiency Below Threshold (Bank 2)

means that the 02 sensor is not reading the cat. This usually happens when a 02 goes bad. If it was your cats, it would buck when accelerating.

Only way to check the cats is pull them off and see if it looks like someone dropped a frag grenade in it.

No, the cat is not necessarily plugged to bring codes out. If you would simply read what the code means and how the system works you would understand.

You can check the cats with a borescope without removing them, just thru the bung.

But being "High flow" cats is totally normal to get that code, solution? a tune from someone that knows and I do not mean shutting them off.

As it hasn't shown before you will probably go change the sensor, clear the code and won't see it again, that would not mean the sensor was bad.

 

[SteveP]

02s are these cars go a lot quicker when you add high flow. More flow is getting through them and the rear 02s will go bad just as quick. it's a common part to go bad. When these cats go, they go.

 

[1bad65]

The high flow cats are only about 2 months old. I was running no cats for about 2 years, but had to put the high flows on to pass inspection. I re-tuned it when I put the high flows on as well.

 

[SteveP]

The high flow cats are only about 2 months old. I was running no cats for about 2 years, but had to put the high flows on to pass inspection. I re-tuned it when I put the high flows on as well.

They can still go bad. I went through 3 sets of bassani cats in 1 month before i gave up and went off road

 

[lito]

The high flow cats are only about 2 months old. I was running no cats for about 2 years, but had to put the high flows on to pass inspection. I re-tuned it when I put the high flows on as well.

I don't meant that kind of tuning, not checking AF or so, is tweaking the system for these kind of cats.

If you go and change the sensor the probability that the code comes back is high.

The tip is in the description of the code.

 

[1bad65]

They can still go bad. I went through 3 sets of bassani cats in 1 month before i gave up and went off road

I'm considering doing just that. The tune I had with the O/R H is still saved in my tuner and I kept that midpipe. I'd just have to put the high flows back on and hope I don't throw a code every year for inspection.

The tip is in the description of the code.

Not sure what you mean here.

 

[white05gt]

I don't meant that kind of tuning, not checking AF or so, is tweaking the system for these kind of cats.

If you go and change the sensor the probability that the code comes back is high.

The tip is in the description of the code.

I agree that the code will most likely come back. Just so people know, you can test o2 sensors but it's time consuming.

 

[lito]

I'm considering doing just that. The tune I had with the O/R H is still saved in my tuner and I kept that midpipe. I'd just have to put the high flows back on and hope I don't throw a code every year for inspection.



Not sure what you mean here.

The code refers to cat efficiency, mostly, the cat is not efficient enough. If everything is ok, code will always come back, if not 420, 430, or both.

 

[TexasBlownV8]

1bad65...I can teach you how to pass our inspections with high-flow cats.

The p0430 and p0420 codes often happen with high-flow cats, and do not necessarily mean anything is wrong or bad. Moving the O2 sensor further out of the exhaust stream (using spark plug non-fouler spacers) helps.
[With high-flow cats, more flow goes across the sensor, resulting in more signal amplitude getting read by the PCM on the rich/lean alternating spikes; those spikes are counted, and once a threshold of occurrences is reached, a DTC is thrown.]

Your tuner should be able to help avoid these codes, but you can also get through inspection by proper code-clearing and managing your drive cycles after then and being 'ready' while not throwing codes. I've done it for 3 years now in Wilco.

 

[1bad65]

Thanks TexasBlownV8. I believe I've actually met you several times at AAS events. I was at the last SAR event running very bad times.

 

[TexasBlownV8]

Lol, yeah, but you had fun, right? ...well, maybe not, since y'all left early IIRC.

 

[1bad65]

Lol, yeah, but you had fun, right? ...well, maybe not, since y'all left early IIRC.

It was fun to see you guys, but I was pissed about having traction issues and just not feeling well.

I'll definately hit you up at inspection time if I still have this issue. I'm considering just changing out the O2 sensors anyway since the car has 60k miles on it and I hear those tend to go out before that time.

 

[TexasBlownV8]

The rear ones dont go out that often; it's the front ones that'll tend to fail sooner.
You can also datalog the O2 sensors and see what the signals are doing; this can help pinpoint a weak/bad sensor.