01 Sequoia with p0430 code

YOu can take it to an Auto Zone, if there's one around you. The last time my check engine light came on they read the code and told me what the problem was at no charge. I've heard others say the same of Auto Zone.

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P0430 Catalyst System Efficiency Below Threshold (Bank 2)

The ECM compares the waveform of the oxygen sensor located before the catalyst with the waveform of the oxygen sensor located after the catalyst to determine whether or not catalyst performance has deteriorated. Air-fuel ratio feedback compensation keeps the waveform of the oxygen sensor before the catalyst repeatedly changing back and forth from rich to lean. If the catalyst is functioning normally, the waveform of the oxygen sensor after the catalyst switches back and forth between rich and lean much more slowly than the waveform of the oxygen sensor before the catalyst. But when both waveform change at a similar rate, it indicates that catalyst performance has deteriorated.

Detectiong Condition: After engine and catalyst are warmed up, and while vehicle is driven within set vehicle and engine speed range, waveform of heated oxygen sensors have same amplitude (2 trip detection logic)

Trouble Area: Gas leakage on exhaust system Heated oxygen sensor Three-way catalytic converter

Check gas leakage on exhaust system. NG Repair or replace. OK- Check heated oxygen sensor (bank 1, 2 sensor 1) NG Repair or replace. OK-Replace three-way catalytic converter.

Good suggestion. Also make sure you do a tune up if not done recently. Either the converter is bad or the cylinders are dumping too much unburned gas, overwhelming the converter.

This is usually a code showing the symptom and not the cause.

Now is there a bad batch of converters for this truck?

Check with a local muffler shop about welding the necessary fittings on an aftermarket generic cat so it fits your truck. My S&S headers include aftermarket cats, and they work well.

Try adding 3 oz. of acetone per 10 gallons of gas when you fuel. It might work. Give it several tanks to clean things up. You also might try running FP60

for several tankfuls. It it more than pays for itself in fuel savings, stick with it. Don't be surprised if your engine runs rough before it runs smooth while cleaning the combustion chamber. When carbon deposits are partly removed, the remaining deposits may have rough edges that upset the smooth flame propgation front.

Ken

Thank you for the run down. This helps direct my efforts, though I need a little more help

1) Is there a good way for me to check the exhaust system for leeks at home? I would guess a shop uses some sort of probe with a sensor, but how can a shade tree mechanic do the same thing? Also, would a leak that caused this issue have to be in a particular area (between the o2 sensors) or could it be anywhere from the exhaust manifold down?

2) How do I check the O2 sensor? I have an obdii connector for the car (that's how I pulled the code in the first place) and have been playing with some frewware obdii software, but I'm not certain I'm getting what I need. I'm guessing I need to watch the voltage levels on the appropriate sensor and make sure the max and min's are within operating range? If the sensor were bad, though, wouldn't that through another system code?

3) I don't know that the plugs have ever been changed in this vehicle as we bought it new. I will take care of that, but could poor ignition cause this error without causing another code to occur?

4) I don't understand how an exhaust leak could cause this problem. Could somebody explain that?

5) Can other measures be looked at to better focus in on the problem? Long or short term fuel trim ratios?

Thanks, Kevin

Good idea no matter what, but I don't quite understand it in this context. If the fuel cylinders are dumping an excess of unburned fuel into the exhaust system, wouldn't the upstream o2 sensor sense this then feedback this info so timing or fuel distribution would be adjusted to try to overcome the problem? I would think this would either "fix" the issue or result in a poor running vehicle due to overcompensation.

Thanks, Kevin