P0430

[Ryan Grover]

Hello all. While driving my friends 07 expedition I noticed the check engine light was illuminated. I stopped at an auto store and had them hook it up. The code was "P0430" which is "catalyst efficiency below threshold bank 2." If anyone else has had this code was it the O2 sensor or the converter? Thanks in advance!

 

[1955moose]

It can be either. Best to have you or friend run fuel trims. Theirs posts here describing how. If the cats on that side are suspect, the reading's can be checked by a gauge screwed into 02 sensor port, or using a digital heat gun. Did your friend have a misfire in the past that went unattended? That will usually burn out a catalytic converter quick. Are you just borrowimg this vehicle? Or is it a possible purchase?

Sent from my N9131 using Tapatalk

 

[Ryan Grover]

She is not mechanically inclined and I myself am here in Florida for the holidays. She is allowing me to use the vehicle for my stay. I'm unsure of a misfire but today probably 20 min after seeing the MIL on I was just exiting from a highway (on an incline) and had a slight load on the engine at a low rpm and it felt like a couple "misfires." Thought for sure it was going to be a misfire code.

 

[JExpedition07]

You’d be surprised how bad it needs to be misfiring to set off the CEL. It will be apparent to you before the computer lets you know.

 

[JExpedition07]

Relevant

 

[bobmbx]

She is not mechanically inclined and I myself am here in Florida for the holidays. She is allowing me to use the vehicle for my stay. I'm unsure of a misfire but today probably 20 min after seeing the MIL on I was just exiting from a highway (on an incline) and had a slight load on the engine at a low rpm and it felt like a couple "misfires." Thought for sure it was going to be a misfire code.

The P0430 code is based on a temp delta across the converter. Clear the code and you may never see it again.

A clogged cat can present symptoms of a misfire by literally choking the engine (not letting the exhaust gasses out), and if its bad enough, the engine won't even run.

 

[Ryan Grover]

ok, so I will clear the code tomorrow and send an update if light comes back on.

 

[Habbibie]

Hello all. While driving my friends 07 expedition I noticed the check engine light was illuminated. I stopped at an auto store and had them hook it up. The code was "P0430" which is "catalyst efficiency below threshold bank 2." If anyone else has had this code was it the O2 sensor or the converter? Thanks in advance!

It's your friend's car, does it really matter? Are you going to fix it for them? are you paying for the repairs?

I dont get it, you went through the whole trouble of creating a profile here just to ask a question about a friend's car...

By the way next time, save yourself the headache and go on yahoo answers if all you need is one random question answered... much much easier!

 

[Ryan Grover]

So I cleared the code and 62 miles it came back on. I’m going to find a better scan tool to and check waves on the O2 sensors. Hopefully it’s just a bad bank 2 sensor.

 

[lbv150]

Been there done that, sorry to say it needs a CAT. Or

 

[rjdelp7]

The code means, your Cat is below California's code of 97% efficiency. Ebay sells Mustang O2 'off road' MIL eliminators. They plug into harness at the rear O2(only for emissions) sensor. They trick the computer with correct voltage and they work.

 

[lbv150]

The code means, your Cat is below California's code of 97% efficiency. Ebay sells Mustang O2 'off road' MIL eliminators. They plug into harness at the rear O2(only for emissions) sensor. They trick the computer with correct voltage and they work.

Yes and the $3 capacitor and resistor do the same. Works great.

 

[Ryan Grover]

Well here in Florida there is no inspection. So it doesn’t matter if the light is on. Basically when your hard into the throttle anywhere 3k rpm for higher it shutters and lacks power. I just switched the bank 2 sensor 2 and took it for a drive. Still does the same thing.

 

[TobyU]

That code will not make it run differently at all.
If it's shuddering it either had a mis (plugs and coils) or is starving for fuel (pump pressure).

Get a scanner and look at test results for each cylinder misfire to see if any one or two have a lot more than the others.

Codes 0430 and 0430 almost always mean weak converter from running too long with engine miss (sometimes flashing check engine light) or one using oil and coating inside of converter.
But it will still run perfectly with full power and no issues.

 

[Ryan Grover]

So I changed the bank 2 sensor 2 a few days ago. At exactly 200 miles I was driving and was making a lane change and accelerated slightly and the check engine light came on for about 10-15 secs flashing and then went out. Still shuttering and lack of power. If there was a misfire detected you would think the computer would throw a code no? I don’t understand. (Any nasty or rude comments keep to yourself. I don’t have time for you.)

 

[TobyU]

There's two kinds of codes and then there's misfire accounts. Once the check engine light pops on there will be a code stored but sometimes it's possible in some cars for the light to flash and not have it stored code. A flash means that you have a dead cylinder misfiring all the time and it's a warning for you to get it serviced very soon.
Those are what most people call set or hard codes and then you have pending codes. You can have all kinds of pending codes and the check engine light not come on at least not for a long time.
Then you have missed our accounts which is my favorite diagnostic tool especially when it's only missing intermittently and you can't get it to pop the check engine light or even have a pending code. You reset the check engine light and that clears out the misfire counts.
Then you started and let it idle and you can check your misfire accounts and then we'll probably be all at 0. Different scanners show it in different ways some people call it 06 mode or there is a dollar sign or six string or something like that. My scanner has it at the very end of the test results and spells it out as misfire counts cylinder number 1 and then shows you a number. It also shows you that the number is less than or greater than 200 and shows you if it passes or fails but that's kind of irrelevant early on.
If I go out to any of my town cars or 5.4 in trucks or even 6.8s and go in the scanner and clear the codes then start it back up and let it idle and then scan for codes again and look at the test results all eight cylinders will show zero misfires. Then while it's still running if I reach under the hood and unplug a coil pack or a fuel injector to disable a cylinder for 10 or 15 seconds and then get back inside and scan for codes again it will show a number of how many times is since the misfire. They will still be no check engine light popped no code stored and no pending codes but I will see which cylinder is misfiring from the test results. This is why it's my favorite diagnostic tool.
An 0420 or 0430 code 90% of the time means your converter isn't doing its job as well as it should but your oxygen sensors are doing their job perfectly and picking out the difference between the pre and post sensor 1 Sensor 2 that the converter is not doing its job. For years people have replaced oxygen sensors for these codes and it doesn't change anything. I have shelled out 40 to $70 before for an oxygen sensor back 10 years ago or so maybe longer before I learned this. It's also possible to have a misfire for so long or a converter become so damaged that it kind of melted together and causes a massive restriction and become a plug converter and they will run low on power but this doesn't come and go. I'm not really seen or heard of many converters that plug and unplug or anything like that.
So if yours runs fine for a while until the occasional issue or you give it some part throttle and it starts to stumble and have low power I just don't think it can be converter related and I can guarantee you it's definitely not O2 sensor related.
Oxygen sensors were put on cars for emissions reasons. All this hype about changing them to get better fuel mileage in just so they can sell parts at AutoZone and so Bosch can sell sensors.
Yes, cars can adjust the fuel mixture and fuel trims and they do this based on the results they get from the sensors however in the real world you're much more likely to have a vehicle that's running lean do to a vacuum or intake leak so the sensor will pick it up in the computer will richen the mixture as far as it can trying to make the engine run the best it can which uses more fuel. It is possible I guess for a sensor to fail and make the car think it's running really really rich and it would lean out the mixture which would save you fuel but it would probably paying some but it doesn't make much difference because when things get too out of whack it goes into a Fail-Safe limp mode anyways just like if you unhook the sensors and they still run pretty well this way.
The most likely answer to your symptoms is a misfire or low fuel pressure from a weak fuel pump.

 

[Ryan Grover]

Well thanks for all the info! I’m pretty sure the plugs and coils have been changed recently (she said a shop did it.) I don’t have access to a scan tool other than going to a shop. Mine is in NY at home. So should I do a pressure test on the fuel pump?

 

[TobyU]

The parts stores have a scanner and some of the guys know how to read the other menus other than just check engine codes.
I would go there first.

You could hook a gauge up to the rail and drive around looking at pressure. The fords need an adaptor but I have used old hvac gauges since long enough to lay a towel on windshield and run under hood /cowl and latch hood down at least first notch so you can drive and see pressure.

Just water, oil, coolant, moisture getting on the coil boot in the well will cause misfires.
You could pop them up and blow them out and wipe off boots good.

 

[rjdelp7]

Listen, right after switching off the engine. I read a clogged converter, will cause an air 'hiss', as the excessive back pressure is vented, through the PCV or EGR.