119,923 miles i get a PO430 code. truck is completely stock. dont know if its an 02 sensor or a cat. granted its a cat going out, what are my options? this is a california truck so i dont know what i can do with keeping smog in mind. aftermarket cat(s) no cats, hollow cats, ....? is there a warranty on the cats? i cant find anything other than for camaros and vetts in 2000 and 2001. any help would be great. im not putting another mile on my truck till i figure this out.

 

8 year or 80,000 on the factory cat's which ever comes first.

Here is gm's deffinition on 03 silverado 5.3

DTC P0430

CIRCUIT DESCRIPTION
In order to maintain low emissions of hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx), the engine controls system uses a 3-way catalytic converter (TWC). The catalyst within the TWC promotes a chemical reaction, which oxidizes the HC and CO that are present in the exhaust gas. This reaction converts these chemicals into harmless water vapor and carbon dioxide. The catalyst also reduces the NOx which converts into nitrogen. The powertrain control module (PCM) monitors this process using heated oxygen sensor (HO2S) bank 1 sensor 2, which is located in the exhaust stream past the TWC. The HO2S bank 1 sensor 2 produces an output signal which indicates the oxygen storage capacity of the catalyst. This determines the catalysts ability to effectively convert the exhaust emissions. If the catalyst is functioning correctly, the bank 1 of the HO2S 2 signal will be far less active than the signal that is produced by bank 1 of the HO2S 1. This indicates that the TWC oxygen storage capacity is below an acceptable threshold.

The PCM performs this diagnostic test at idle. When the conditions for running this DTC are met, the following occurs:


The PCM captures the current rear HO2S rich-to-lean status.
The air-to-fuel ratio transitions from rich to lean or from lean to rich, depending on the captured rear HO2S rich-to-lean status.
The air-to-fuel ratio transitions a second time opposite the first air-to-fuel ratio transition.
The PCM captures the response time of the front and the rear HO2S when the air-to-fuel ratio transitions occur. The HO2S response time goes from less than 300 mV to more than 600 mV , and from more than 600 mV to less than 300 mV .
The PCM measures the time necessary for the rear HO2S voltage to cross a reference rich-to-lean threshold, minus the time necessary for the front HO2S voltage to cross the same rich-to-lean threshold. The difference between the front HO2S time and the rear HO2S time is the oxygen storage capacity of the catalyst. This DTC sets if the time exceeds a predetermined threshold.

CONDITIONS FOR RUNNING THE DTC


DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0120, P0125, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0160, P0161, P0171, P0172, P0174, P0175, P0177, P0178, P0179, P0200, P0220, P0300, P0325, P0327, P0332, P0335, 336, P0341, P0342, P0343, P0351-P0358, P0442, P0443, P0446, P0452, P0453, P0455, P0496, P0502, P0503, P1125, P1133, P1153, P1258, P1514, P1516, P1518, P2108, P2135 are not set.
The intake air temperature (IAT) is between -15°C and +85°C (+5°F and +185°F) .
The barometric pressure (BARO) is more than 74 kPa .
The engine is operating.
The engine coolant temperature (ECT) is more than 70-120°C (158-248°F) .
Since the end of the last idle period, the engine speed is more than 900 RPM for the one of the following amounts of time.
45 seconds for manual transmissions
40 seconds for automatic transmissions
The Closed Loop fuel control is enabled.

CONDITIONS FOR SETTING THE DTC
The PCM determines that the oxygen storage capability of the TWC has degraded to less than a calibrated threshold.

ACTION TAKEN WHEN THE DTC SETS


The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame/Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC


The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.

A catalytic converter which has been discolored may be due to an engine running rich, lean or had a previous sever misfire. Verifying the fuel trim percentages may be of assistance in determining if such a condition exists.

 

To keep it legal you will need to have them replaced.

 

Penny wise, I would swap the O2's between banks and see if the problem followed the O2's or stayed with the bank 2 cat before I cast the first coin.

 

well as soon as i get the truck back from the dealership (i blew my tranny out about 2 hours ago) ill be sure to swap out the o2 from bank to bank. been having a tough year with this truck. i baby her and dont push her hard or pull anything. january i had about 200 miles left on my warranty when the 1st tranny went out. now 11 months later it happens again.

 

11 months and a second one...that's suspicious. What was the specifics of the first? and second?

back on topic...yeh, to stay legal in good ole cali you'll need $$$ replacements. But like mentioned earlier, swap B1S1 with B1S2 and B2S1 with B2S2 and pull battery for about 10 minutes (5 extra minutes passed what's needed) and start from scratch.

What really blows, if the o2's aren't the problem it doesn't necessarily mean your cats are BAD it just means they aren't meeting the specified parameters. Ugh.

(*disclaimer, pulling that battery for 5 minutes erases idling fuel trims and your truck may idle funny for a few miles. AND it makes your truck have to go through all the drive cycles again. But what do you care, it's been in the shop with the battery unhooked anyway right? )

 

Turns out it was the transfer case this time. not the tranny. if the cats are not performing 100 percent, can I turn off the rear o2's and then I won't be getting that dash light (in theory right ) ? I'll eventually be ditching the cats and all anyways. I'll will be keeping them so if I sell the truck way down the road, no issues. anyone know if I can use my diabo sport tuner to shut off the rear o2's?

 

My diablo couldn't....but it is old. Anyone with HPT or EFI Live and a license for your year/model can set those codes not to report (lights off). Another option is O2 simulators out on the market.

 

well if I'm going to get it tuned eventually, might as well do it right after I dump the cats. I'm over worrying about being legal in California. This state is already on my **** list. Actually I might do the simulators until I find a cam that suits my need and any other modifications I might do.