ronjenx

Parts Covered for 8 years or 80,000 miles
If your vehicle has one of the following parts, this
Federal Emission Warranty covers that part for a
period of 8 years or 80,000 miles, whichever occurs first.
These limits are counted from the time when your
Basic Limited Warranty begins under 2.1(E). The
covered parts are:
• catalytic converter; and
• powertrain control module.

JMP8562

this might also help
Explaining Trouble Codes PO420 - PO421- PO430 - PO431



WHAT IT MEANS WHEN YOUR GET A CODE READ OF PO420 OR PO430

It is important to remember that if your "Check Engine Light" illuminates and someone just simply reads a code of PO420, 421, 430 or 431 this does not necessarily mean the Catalytic Converter is bad! All that code says is either Converter operating below efficency or Converter operating below threshold. No where in the interpretation of that code does it say the converter is bad. Your vehicle may very well need a Catalytic Converter but to determine this, your mechanic or technician should perform proper engine diagnostics. Just reading a simple code is NOT considered performing diagnostics. The following material should give you a better understanding of what proper diagnostics consist of and how they should be performed. If after reading this material you still have questions please give us a call, 888-651-0770, and we will do all we can to help you solve the problem.



When your vehicle generates those emission codes it simply means that the converter is not able to function properly. Remember that the catalytic converter is at the very end of the emission diagnostic system, and a number of things can go wrong upstream of the converter that can cause. a PO420 (or PO430) MIL light illumination.

PO420 or PO430 CODE CATALYTIC CONVERTER FAILURE DIAGNOSTICS
Following is a list of procedures that should be accomplished before the final determination that a new catalytic converter is needed. These are known as diagnostic procedures and go far beyond someone just performing a simple code reading and then declaring a bad converter is present. That is not performing proper diagnostics! The following items will outline proper diagnostics in determining whether a converter is good or bad.

EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up (masking the original reason for converter failure).

VEHICLE TEST

If possible, test-drive the vehicle and note any driveability issues that may indicate fuel or spark delivery problems such as hesitation, stumbling, spark knock or signs of misfire.
Idle smoothness. Check for any signs of surging or roughness, indicating misfire or improper fuel delivery.
Check the tailpipe, particularly immediately following start-up, for any smoke indicating too rich AFR (black smoke), water/antifreeze (white Smoke), or oil (blue smoke).
Listen to engine carefully for any signs of vacuum or exhaust manifold leaks.
Inspect intake system for signs of oil indicating excessive blow-by or cracks that may cause leaks.
Inspect spark plugs/wires and air filter.
Scan tool test.
Do not reset MIL light!!
Read the OBD-II readiness tests to ensure all tests have been completed. If the tests have not been completed, chances are the MIL was recently reset, possibly hiding intermittent problems.
Read trouble codes (if any) and inspect as necessary.
Read pending trouble codes (if any) and inspect as necessary.
With engine running and at operating temperature, read scan data list. This is typically a table listing all available sensors and outputs.
Look at Long Term Fuel Trims (LTFT). These show the amount (in %) the computer is modifying fuel delivery, based on the 02 sensor feedback. Positive numbers indicate the computer is adding fuel, negative numbers indicate the com*puter is removing fuel. Large positive numbers (>10%) should be investigated further as they indicate the computer is adding more fuel than originally designed.
Look at the O2 sensor output signals. Sensor 1 is before the converter, Sensor 2 is behind the converter, Bank 1 and 2 are typically used in V-configuration where Bank 1 is on the side Cylinder 1 is located. Some inline 6 cylinder engines have Bank 1 as Cylinders 1-3 and Bank 2 as Cylinders 4-6. The sensors are usually abbreviated as O2S1B1 (O2 Sensor, Bank 1)
Sensor 1 output should be very active and oscillate rapidly from approximately 0 to less than 1 volt. If the signal tends to show high voltage with little fluctuation, excessive unburnt fuel is reaching the sensor. If Sensor 1 shows low or no voltage, the sensor could be defective, or there might be an exhaust leak in front of or immediately behind the sensor, or there could be a lack of fuel delivered to the combustion chamber. If the sensor does not respond to a rapid accelerator kickdown, chances are the sensor is defective. If it does respond, an exhaust leak or lack of fuel is indicated. (The preceding test must be done after the engine and exhaust system have been allowed to fully heat up.)




Sensor 2 should show a fairly steady signal. It is not critical what the signal is, only that it does not oscillate as frequently as the front. If the signal is above 250mV, the sensor is fine. If it is below, check for activity by rapid accelerator kick-down or by raising the engine speed to approximately 2000 rpm. Any movement indicates the sensor is fine.
The material above is designed to give our customers a better insight to their need of a catalytic converter replacement. If someone has told you that a new converter is required on your vehicle just from the simple reading of a "check engine light" code they are not doing their due dilligence and not performing complete diagnostics on that vehicle. Cars today are not smart enough to tell us what is wrong with them just by generating code, they simply tell us what hurts and it is up to a technician or mechanic to interpret those codes and then get to the root of the problem.

If you still have questions or would like us on to talk directly to your mechanic on your behalf, please give us a call at 888-651-0770 and we will be happy to assist you.

blockrockin

wow thats some good info ! thanks.. I'm getting the 420 code.. i have a super charger and rockkralwer lift.. and had the exhaust changed to clear the lower front control arms... the 2nd resonators/converters where removed . so I'm guessing thats why I'm getting the 420 code ...if i clear it . i get the code back after i give it a good amount of boost.. sometimes it gives me the p0130 code for the 02sensor.. but i replaced the o2 sensors.. I'm guessing that the code is coming from the back pressure change with the exhaust work.. and thoughts... or maybe i do need a new converter ?

Badd Andy

had the same about 4 mos ago, they replaced my cat under warranty, problem solved

blockrockin

i took it to the dealer.. they were cool enough to offer to replace the cats under warranty ..even though i have alote of mods.. and a supercharger... but when they looked.. they said they couldn't because they need the original cats to send back for warranty and since i dont have the seconds ones that was a problem.. i still passed emissions (when the check engine light was off) ..so i guess its nothing to serious.

JMP8562

well i was running the E-3 plugs and decided to go back to the stock plugs and about 500mi later the ck eng light came on po430 lookd up the code on the forum and googled it everything checked out ok and as far as warrenty i have 107000mi so that was not an option all i did was disconnect the battery for a few and its been about 1000mi so far and the code did not come back
just a FYI

JMP8562

WELL im at a loss all summer no codes and now the weather is getting cooler that code came back ?

dukedar

I went through this at the beginning of the year and worked with the dealer. I got the JK in June of 2010 and it sporadically threw the PO430. I either reset it with a battery disconnect, or later a scanner (I bought one because of this). It almost always came back after 3 weeks. When I eventually took it in around Jan. of '11, they replaced one 02 sensor at my expense (~$60). It threw the code 3 weeks later. I brought it back and bitched some more, and they said it was a leak and re-tightened the cat (apparently they had taken off the y-cat to change the sensor). 3 weeks later it came back... I went back and bitched some more. I was past 100,000 kms and out of warranty, but apparently the emissions warranty applied to me as well and it was also 8 years and some kms (as mentioned here). After some rumination they cam back and said that they would replace the cat. They ordered it and i went back a week later. No PO430 since!

From reading here, it always seems to be the cat, which was why I brought it in. Look up the price on this thing and trust me you will want to push the dealer to fix it!

Darren

JK_Oman

I had that code for almost 2 and half a year since I installed my magna flow cats but since few days I installed my long tube ripp headers it's gone

In my case I was suspecting the catalytic convertor was not functioning well.

osros

Well this has started happening to me also same code pops up after 24 to 48 hrs thing is its being stored error so not a constant error that the dealer can diag with trying a checklist of things to look for. They are now checking for any leaks, they are trying to avoid the catalytic convertor change for $1200 installed but all points to it. No warranty over 80k miles. I guess if this pops up for anyone else and your under your 8 years or 80k miles get it changed out asap.

I can go to a muffler shop and put in some cheaper aftermarket job but i just dont like going down that road.