Scottie i got a 2005 BMW 320i, automatic transmission with 136250 miles and i have a P0430 code, question is i’m not planning to fix the catalytic converter so how long can i keep driving the car with this malfunction and is it a good idea ?
a failed O2 sensor is not good for your engine
an exhaust leak is not good for your health.
A failed catalytic converter could make your engine run like crap.
A code P0430 may mean that one or more of the following has happened:
- The catalytic converter is no longer functioning properly
- An oxygen sensor is not reading (functioning) properly
- There is an exhaust leak
Why the down-vote ... does that not answer your question?
It's not a Chevy Cobalt. It's a BMW.
Keep running it with the fault and see what happens. I've said it before, I'll say it a million more times I'm sure: German cars are finely tuned machines that require constant maintenance. You fix the problem when it comes up to keep all the tight variances in line and prevent damage.
This is why I tell people: don't buy or own a high mileage German car unless you plan on expensive maintenance items.
If the converter price is too much for you, wait until you price a motor. Like I said, keep on going at your own peril.
@dontKnowler
the pcm expects a steady voltage from sensor 2. If I obstruct sensor 1 (with carbon deposits for example), then it will also produce steadier voltage and delta will decrease.
If I introduce fresh air (LOTS of oxygen) into the exhaust system before sensor 1, it will be more than the CC can process. Both sensors will report high oxygen content.
You check ANY OBD resource. Exhaust leak is always mentioned as a possible cause.
Additionally,
When the pcm detects a problem with #1 O2 sensor, the downstream O2 sensor becomes the primary fuel feedback signal. The CC is a very expensive and important piece of equipment. A lot of pcm programming is dedicated to preserving the CC.
"the pcm expects a steady voltage from sensor 2"
If by steady you mean "more or less constant" - then Not at all. There were times when I drove with Sensors 1 and 2 output graphs on my screen for weeks, so - it definitely did not work this way, sorry, at least not on my two cars. Sensor 2 voltage always has very significant engine load-dependent fluctuations. Only in the ideal world the cat (even a 100% new and well-functioning one) does its job 100% under all conditions - in the real world it is not the case. The Sensor 2 fluctuations are indeed smaller than those of Sensor 1 (due to the cat influence), but they are present, and are expected by the ECU. IF Sensor 2 starts rendering a truly steady signal, some time after that the ECU will interpret this constant signal as a Sensor 2 malfunction sign, and will trigger a Sensor 2 malfunction code.
"If I obstruct sensor 1 (with carbon deposits for example), then it will also produce steadier voltage and delta will decrease"
If I understand your point correctly, you believe it possible, for a malfunctioning (due to obstruction) Sensor 1, to be mimicking the Sensor 2 output signal curve precisely enough (with a delta small enough) to trick the ECU into thinking it is the cat´s fault? Theoretically, this could be the case. But practically, I dont believe it can work this way. What will happen, is the following: the obstructed Sensor 1 will have less area of its sensing element contacting the gas flow. So it will be signalling less O2 to the ECU than normal. The ECUs reaction will be making the fuel-and-air mixture even more lean, in order to get the Sensor 1 readings back to normal (in order to increase the residual O2 contents). Then after some time the ECU will notice that these attempts did not help to get the Sensor 1 readings back to normal (remember: normal is no more possible due to sensor obstruction), and this will trigger a Sensor 1 fault code - not the cat inefficient code.
"If I introduce fresh air (LOTS of oxygen) into the exhaust system before sensor 1, it will be more than the CC can process. Both sensors will report high oxygen content."
This I can confirm out of my own experience - I tried blowing compressed air into the exhaust gas flow. BUT in this case what will be triggered are O2 malfunction codes (since the ECU will notice that both sensor readings dropped to their bottom limits and tend to stay in that range).
In addition to that, it is normally not so easy to inject smth int the exhaust system. It exhausts gases due to the fact that its internal pressure is higher than the environmental pressure around it. So if you drill a hole in your exhaust pipe and attach an air balloon to it, you will see that it inflates, not deflates. In other words, exhaust gases coming out of an exhaust pipe hole is a much more probable situation that surrounding air getting sucked into this hole.
I have read theories claiming that due to pulsations gases can still get sucked into the exhaust, but, frankly, I cannot understand the possible physics behind. That would mean pressure alternating in the exhaust from positive to negative and back again all the time, which in my view is incompatible with the exhaust gases giving relatively steady rotation to my turbine - and my turbine rotates just fine....
"When the pcm detects a problem with #1 O2 sensor, the downstream O2 sensor becomes the primary fuel feedback signal"
Are you sure? On my two cars, when Sensor 1 fails, the ECU switches into limp mode when it no more relies on O2 sensors at all, but starts using some firmware-default table values. When I think of it, the Sensor 2 output signal appears too - how shall I put it - retarded and non-idicative (due to the influence of the preceding cat) to be used for determining the fuel-and-air composition. The O2 contents in the gas flow after the cat are much more indicative of the cat´s not-linear efficiency under current load and temperature, than of the air-and-fuel composition in the cylinder.
/All the above is just my opinion based on my wn experience, and is not meant to be The Ultimate Truth/
*non-idicative = non-indicative
P0430 means your cat converter is just too old to be efficient. As long as it does not restrict the exhaust gas flow, you can drive like that as long as you like. It is not engine-damaging, nor is it a reason for the ECU to switch into limp mode (as O2 sensor errors are - but your error is not an O2 sensor error). Just bear in mind that you will be damaging the environment, that you will not pass emission tests, and that you may face slightly higher fuel consumption. The latter is due to the fact that the ECU re-tests the cat regularly, and each time, before the ECU really believes that the cat is inefficient, it will first assume it just has not reached working temperature and will spend some extra fuel trying to warm it up.
All the above is based on my experience, and may not necessarily apply to your car - the algorithms of your ECU may differ.
All right, now it’s more clear, appreciate you for that!
First, make sure the cat is not functioning properly. You may have leaks in the exhaust system or faulty O2 sensor that trips the cat code. If you realized that the cat is no good, you can still drive the car as long as it is not clogged up.
Noted, thank you!
Normally, P0430 means that both O2 sensors are fine. This error means that the readings of the second sensor - the one at the cat exit - mimic the readings of the first first one - the one at the cat entry - too closely / too well. In other words, both sensors provide almost the same readings, although the cat should have introduced a huge difference / a noticeable delta between these two readings by combusting the not-fully-combusted gases.
This can practically only happen, if both sensors are fine, and the cat is inefficient. So pretty little room for guessing with this code, luckily.
P.S. An exhaust system leak does not do this either - it disrupts readings, but does not and can not eliminate the delta between the two O2 sensors´ readings, which is (or should be) introduced by a functioning cat.
I agree that the CAT is loosing its efficiency! The only problem you will have is if you have emissions testing. My son-in-laws Pilot has the same code with 230k on it. Runs like a top! When its emission time we do a code clear and do the drive cycle before he hits the emissions test. Works everytime. Again the car runs great otherwise! Otherwise it would be about $2800 repair and its a 2006 with lots of crusty bolts underneath.
