P0420 & P0430 Codes

[earthrealm]

So Bank 2 LT FT is 17.1%? That is a bit high. I would guess you have possibly an exhaust leak or extra air getting into bank 2 side some how. 17.1% means it's adding 17.1% more fuel to the vehicle, which means it's seeing more oxygen somewhere. There's a number of things that could cause it, but if it's isolated to Bank 2 I'd guess something on the exhaust side of the spectrum.

wow spot on!..my mechanic said i hv an exhaust leak last week, when i went to replace my bad hub/bearings.
didnt take him serious, cos i havent observed or heard any strange sounds from the car.
will most def go back and have him tackle the leak.

and here i was thinking along the lines of dirty plugs/injectors etc.
so if both LT FTRMS of both banks were that high, what would you deduce to b the cause?.
is it the ST FTRMS that are related to plugs?

 

[BlackWorksInc]

wow spot on!..my mechanic said i hv an exhaust leak last week, when i went to replace my bad hub/bearings.
didnt take him serious, cos i havent observed or heard any strange sounds from the car.
will most def go back and have him tackle the leak.

and here i was thinking along the lines of dirty plugs/injectors etc.
so if both LT FTRMS of both banks were that high, what would you deduce to b the cause?.
is it the ST FTRMS that are related to plugs?

You tend to use Long Term Fuel Trim for diagnostics because it's more stable, Short Term is more erratic (i.e. if you goose the gas you'll see Short Term pop up and down real fast). Long Term is what the vehicle is doing over the long run to maintain a proper air/fuel ratio. Short Term tends to be what the vehicle is doing now to meet demand, so it varies based on load and such.

If you had Long Term Fuel Trims that were equally high on both sides I'd suspect something that was more common between the two banks. Things such as injectors, intake gasket, loose air hose on the intake, bad fuel, ect. The fact that it was very starkly different on one bank and that it was getting too much air made me thing exhaust leak as a likely culprit, that doesn't mean it couldn't be an injector or two on that side or an air leak at the intake manifold to cylinderhead on that bank. But that seemed like the most plausible cause off the top of my head.

 

[earthrealm]

[MENTION=66389]BlackWorksInc[/MENTION]
so the mechanic said the leak is from the exhaust manifold, that the gasket there is bad, and needs to be replaced/
you have any idea of a leak occuring there, how difficult is the ops, and anything special i should be aware of?

am certain the bolts would be rusted, and probablly break during removal..is this an issue?..is there stuff i need to buy before starting the ops.

 

[BlackWorksInc]

[MENTION=66389]BlackWorksInc[/MENTION]
so the mechanic said the leak is from the exhaust manifold, that the gasket there is bad, and needs to be replaced/
you have any idea of a leak occuring there, how difficult is the ops, and anything special i should be aware of?

am certain the bolts would be rusted, and probablly break during removal..is this an issue?..is there stuff i need to buy before starting the ops.

Yeah those bolts look nasty... Well the best you can hope for is if they do break they leave you enough meat to use a stud remove to get them out of the head.

If I recall the V6 isn't as bad as the V8 for replacing the manifold gasket (you may want to check the manifold for cracks/holes while it's off. It's just going to come down to the rusty/seized bolts. You can try getting the engine nice and hot and soaking the bolts in PB Blaser or Rust Penetrant and letting it cool off while soaked before doing the job?

 

[T4panther]

Fault code P0430

I have a doggle on my fuse box and this fault came up "P0430 - Powertrain. Catalyst System Efficiency below threshold (bank 2)."
I've read a bit of these replies. I think by changing the fuel quality helps. My daughter accidentally put 20 litres of kerosene in the tank. (Was in a blue fuel can and didn't know there was a difference). Anywho, my mechanic said to fill the tank with supreme, high octane fuel and will run it's course.
I did that and the fault code didn't come up again. Now that I have been filling it with regular fuel (89 octane), it's giving me that fault code again.
My check engine light comes on more than not and my airbag light is also on more than not.
It's too expensive to be using the supreme fuel all the tine but I think it needs it once in while. I'm in Alberta, Canada and we have the cheapest fuel prices in the country and still too expensive. Gas prices are ludicrous btw.

 

[hdhp65]

just put some long tube headers with a o2 simulator on it and you wont have to worry about replacing such expensive items

Really?

 

[GoBucks!]

Just as an FYI, and hopefully this helps someone else.

I have a '08 V8 4WD 4Runner that was giving me the P0430 code. I've read both that it is on the driver's side and passenger side, but most seemed confident that it was a driver's side issue on the V8. Wrong.

I tried everything on the driver's side: new O2 sensors, new PCV valve, anti-fouler plug, etc., but nothing worked. The code kept coming back, more frequently, and eventually within a day or two each time of clearing the codes.

I finally tried the shop-vac blowing into the tailpipe trick to find exhaust leaks and found a large one between the cat and downstream O2 sensor on the passenger side. Got that exhaust leak fixed and the code hasn't been back.

TLDR: On a V8, the P0430 is a PASSENGER side cat/sensor issue.