What controls or determines the LTFTRM & STFTRM? When my 05 gives the P0430 code, I generally look at the data to see wher the O2 numbers are...they generally agree left to right both 1 and 2 on banks 1 and 2...but the fuel trims are way different from bank 1 and bank 2...

For example, the LTFTRM for Bank 1 is 0.8 fluxuating to 3.1...But bank 2 is like 8.0 or so...Same thing with the STFTRM...way different between bank 1 and 2...

Is this indicative of a bad fuel injector, or indicative of a bad cat...
I have mentioned here before, that I have been getting the P0430 for about 3 years now...I just keep resetting, and go on...summer time, I can go about 300-500 miles between codes, winter is about 150 miles. I even passed smog check last august here in an enhanced smog check area in Northern Ca. between codes...

It is an 05 5.4, and I have had one bad injector which did alot of damage...
I have tried pulling the injectors to do the amateur leak test (paper towels under the injector, key on)...none ever show a leak...so if it is an injector, its intermittent (real intermittent...like ford probably would test and not find a bad injector either)

Any thoughts guys?

Regards!

 

You may be overthinking it. If P0430 is the only code you're getting, look at your O2 sensor volts. You should notice sensor 1 on both banks fluxuating greatly. Sensor 2 on both banks should be holding relatively steady by comparison. But in your case, I suspect bank 2, sensor 2 is fluxuating a lot more than bank 1, sensor 2. If that's the case, replace the converters on bank 2 (or both banks if you're a perfectionist like me). Converters fail most often due to excessive fuel, which a failed injector will cause.

Regarding the fuel trim, it's normal for it to be different between the two banks. This is your computer doing it's job to ensure it's running as efficient as possible. If it crosses a threshold from a mechanical issue (vacuum leak, injector, etc.), your computer will trip a code for it. If it's a specific bank, running too rich or lean, there are codes tripped for that also. I've had this happen. If you have a failed 02 sensor, there's a different set of codes for that as well.

The simplest solution is usually the correct one. Usually.

 

Thanks ESJAY...

Bank 2 O2S21 and S22 seem to change equally as fast, where bank 1 S12 changes a bit slower (more steady)...I can only look at it during idle...

I want the problem to be as simple as an injector or O2 sensor...Cats here in the great state of California are extremely expensive (my only legal option is an OEM Ford cat) as the only aftermarket cat approved for the F150 is for the 4.6l 2wd only...per the California Air Resource Board. I checked Fordparts.com...the cat has come down a little in price at $2100 (was $ 2400). Having a hard time with that...

When my truck is idling smooth, the fuel trims almost agree...just one is about a second behind the other... I'm at 157k miles...want too change injectors and plugs anyway, just trying to save the $$$

Regards!

 

One of many reasons I left The People's Republic of California. CARB is a prime example of wasted tax dollars. I have nothing against emissions controls on a vehicle, California takes it to a whole new level of stupid. I bought my truck new in San Diego a few months before leaving. When I went to register it in Virginia, I had to show the receipt for my truck as proof that I've paid taxes on it somewhere. The DMV clerk was stunned when she saw 9.25%. I think Virginia was 3% at the time.

About your converter, check Tasca. They're usually reasonable on pricing. Search by VIN to make sure you get the correct one.

http://www.tascaparts.com/

 

THAT is the hallmark of a defunct converter.

<cough, cough>...spark plug anti-fouler...<cough, cough>

 

I've done the Radio Shack hack with a resistor and microfarad capacitor. Do a search for "MIL Eliminator". But in California, they use a sniffer if I recall correctly. You can't cheat that.

 

That is the funny part...it passed smog last August...I really thought I was going to fail despite no code at the time...it wasn't even close to failing the tailpipe test...and they dyno test here in my area...that is really what makes me wonder if the cat is truely bad...just got another code P0430 (code and pending code) this am...176 miles since reset...

I have been considering the gotts mod...I'm lazy! It only takes a second to reset the code...

Thanks for your comments and suggestions guys!

Regards!

 

No doubt that the cat is bad from what's described. But you're fortunate that it wasn't bad enough to fail the sniffer. I'd avoid going the MIL eliminator route because if they see anything like that, they'll probably fail you. But you could keep going as-is or try it. Worst case, you just delay the inevitable. Best case is you never have an issue passing.

You could wait for an aftermarket cat to become available. Maybe even call Magnaflow and see if they anticipate CARB approval for your vehicle in the near future. They're based in Orange County and are really great. CARB is the choke-point.

Things to do before going to an emissions test:

Change the oil if it wasn't recently. This does make a difference for reasons I don't have time to explain right now.

Remove your PCV valve and clean it with carb cleaner. Make sure the PCV hose is not rotting.

Make sure the air and fuel filters aren't overdue for a change. Every 30,000 miles is great.

Change your spark plugs every 60,000 miles.

Around 60,000-100,000 miles, remove the throttle body and clean the EGR ports. I'm not sure about the 04+ ones, but the previous ones were prone to clogging.

Replace your front O2 sensors at 60,000-100,000 miles or if you have a failure. Those sensors are what tells the computer how the engine is running and they do get sluggish with time. The rear sensors are only used by the computer to verify the cats are working correctly by comparing the readings with the front sensors. They have no effect on performance.

Run a full tank with two bottles of a good fuel system cleaner. The more you can do highway driving with the cleaner, the better it will work. 3M is my preference. Better yet, you can have the fuel system professionally cleaned by a shop that has the 3M fuel system cleaning tools. Probably overkill, but it's by far the best way to go. I'm not a fan of the Seafoam method because you can blow a head gasket or do severe damage to your engine.

Make sure there are no other issues such as visible smoke, vacuum leaks, misfires, etc.