2000 Camaro v6 auto

Car threw a PO420 code at emissions.

Figured it had something to do with the cat and/or o2 sensor. i had put a new high flow catco cat in a few years ago (welded) but it seems its bad.

went to a shop, and $100 later my suspicions were confirmed - they are saying need new cat and o2 sensor.

since the cat is welded in, they are saying they would need to sub it out (which is dumb) - and the other stop says $880 for the repair, which I think is asinine.

i know a place i can get the labor done cheaper - so I was wondering if/where I should order the cat and o2 sensor from for the job - and what parts in particular i should get

btw I have a 2.5" flowmaster american thunder catback system installed as well

thanks for the help guys

 

for it to code p0420 = catalitic converter low effentsensy
it uses the o2 sensors to test for that.
basical it is seeing the rear o2 change as fast as the front one to give that code.
if you can get the senosr out it should be ok.
but high milage tends to plug up the sensors with carbon, and if someone complains of low gas milage i tell them to change them

 

what are the emission laws around you if you can get rid of all that crap your motor will thank you it likes to breath too

 

varries state to state and province to province.
in quebec ... it's a free-for all practicly. depends how much cops you **** off!!! no inspections until you sell your car that is 25 years or older. no smog test at all ever!
they just look visualy for the components ... sometimes
my converter was rattling and busted up inside on a 99 jimmy, emptied it out and it never even coded before or since???

 

as soon as i get some headers for my car im getting rid of all that sht cats o2 egr no emission inspections in sc baby

 

880$ to replace the cat?

I changed mine a couple weeks ago and cost me $200(including the cat).

 

i need the cat to pass emmision - we are nt like CA here but its still tight in MD

rejk - where did you buy the cat?

 

I would check the O2 Sensor and if bad replace it first, or get an O2 simulator, or just delete the rear O2 sensor from the computer ;-) If you HAVE to get a new cat, look into a high-flow one like Magnaflow sells.


Document ID# 570323
2000 Chevrolet/Geo Camaro
DTC P0420 Catalyst System Low Efficiency

Refer to Engine Controls Schematics .
Circuit Description

To control emissions of Hydrocarbons (HC), Carbon Monoxide (CO), and Oxides of Nitrogen (NOx), a three-way catalytic converter is used. The catalyst within the converter promotes a chemical reaction which oxidizes the HC and CO present in the exhaust gas, converting them into harmless water vapor and carbon dioxide. The catalyst also reduces NOx, converting it to nitrogen. The converter also has the ability to store excess oxygen and release the stored oxygen to promote these reactions. This oxygen storage capacity (OSC) is a measurement of the catalysts ability to control emissions. The PCM monitors this process using a heated oxygen sensor (HO2S) located in the exhaust stream past the three-way converter. When the catalyst is functioning properly, the HO2S 2 is slow to respond to a large change in the HO2S1 signal. When the HO2S 2 responds quickly to a large change in the HO2S 1 signal, the OSC and efficiency of the catalyst is considered to be bad and the MIL will be illuminated if subsequent tests also indicate a failure.
Conditions for Running the DTC

1. Meet conditions for engine warm up. Use the scan tool catalyst data list in order to verify the following.
* No VSS, EVAP, Misfire, HO2S, EGR, ECT, MAF, ETC, IAT, MAP, CMP, CKP sensor, Fuel Trim, or Fuel Injector DTCs set.
* Engine has been running longer than 10 minutes.
* Engine coolant temperature (ECT) is more than 76°C (169°F) and less than 124°C (255°F).
* Baro is more than 75 kPa.
* Vehicle is in Closed Loop.
* Intake air temperature (IAT) is more than -20°C (-4°F) and less than 100°C (212°F).
* Battery voltage more than 10.7 volts.
2. Warm up the catalyst.
* Fully open hood.
* Transmission is in park (automatic) or neutral (manual).
* Set the parking brake.
* Press and hold service brake.
* Each time the engine is started the diagnostic can run up to 18 times. After the ten minute run time, and before the diagnostic runs the first time, the engine must run an additional 5 minutes between 1500 and 2000 RPM. Any additional tests on the same key cycle, the RPM must be between 1500 and 2000 RPM for 1 minute.
* To activate the diagnostic; Return to idle and put the vehicle in drive (automatic) or depress the clutch (manual).
3. Test the catalyst.
* Place the transmission in drive (automatic) or neutral and depress the clutch (manual).
* Within 60 seconds the air fuel ratio will go rich below 14.1 for up to 5 seconds, then it may go lean above 15.3 for up to 6 seconds.
* Using the scan tool check and see if DTC P0420 has passed or failed this key cycle

Conditions for Setting the DTC

The PCM determines that the catalysts oxygen storage capacity is less than a threshold considered acceptable.
Action Taken When the DTC Sets

* The PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
* The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC

* The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed.
* The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
* The DTC can be cleared by using a scan tool.

Diagnostic Aids

Inspect for the following:

* The PCM WILL NOT ENABLE the catalyst test until following conditions are met:
o Engine speed is plus or minus 250 RPM from desired idle.
o Throttle position (TP) is less than .5 percent.
o Short term integrator is between -20 percent and +20 percent.
* The catalyst test WILL ABORT if the vehicle falls out side the conditions listed below while the test is running:
o Engine speed is plus or minus 250 RPM from desired idle.
o Throttle position (TP) is less than .5 percent.
o Short term integrator is between -20 percent and +20 percent.
* The catalyst test may abort due to a change in engine load (i.e., A/C, coolant fan). If this problem occurs use the scan tool to force the cooling fans on return to step 3 in the table then repeat the test.

Important

When using the scan tool to force the cooling fans on use the next list and previous list soft keys to enter the catalyst data list. If the catalyst data list is not entered this way the cooling fan control will be canceled.
* The number of attempted tests is limited to 18 per key cycle.
* More than 6 tests may have to be attempted to get 6 completed tests. An aborted test counts as an attempted test.
* If 18 tests have been attempted, and a decision has not been made this key cycle then turn the key OFF for 30 seconds. Start the engine and perform the Conditions for Running the DTC - including the 10 minute run time.
* After returning to an idle the HO2S 1 signal may stay rich or lean for several seconds causing the test to be delayed.

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

Important:

Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

* Loose terminal connection
o Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
o Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.
* Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.
* Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.
Test Description

The numbers below refer to the step numbers on the diagnostic table:

1.

The powertrain OBD system check prompts the technician to complete some basic tests and store the freeze frame and failure records data on the scan tool if applicable.
2.

If any other DTCs are set, diagnose those DTCs first. A fault in a component can cause the converter to appear degraded or may have caused its failure.
3.

Clearing the DTCs allows the catalyst test to be attempted 18 times and completed up to 6 times this key cycle. If the A/C is ON the diagnostic may not run. The engine must be warmed-up. The converter needs to be warmed-up by raising the engine speed more than idle for the specified time prior to each attempted test. Check and see if DTC passed or failed this key cycle. If the DTC does not pass or fail look for a possible reason that would cause the test to abort.
4.

This step includes tests for conditions that can cause the three-way converter to appear degraded. Repair any problems found before proceeding with this table.
9.

If the three-way converter needs to be replaced, make sure that another condition is not present which could damage the converter. These conditions may include: misfire, high engine oil or coolant consumption, retarded spark timing, weak spark or a plugged/leaking injectors. Correct any possible causes of converter damage before replacing the converter.

DTC P0420 - TWC System Low Efficiency

Step



Action


Values


Yes


No

1


Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?


--


Go to Step 2


Go to Powertrain On Board Diagnostic (OBD) System Check

2


Are any other DTCs set?


--


Go to applicable DTC first


Go to Step 3

3


Important:

If the A/C is left on the following diagnostic may not run.

1. With a scan tool, refer to and record Fail Records and clear DTCs.
2. Turn the A/C OFF.
3. Fully open the hood.
4. Operate the vehicle within the Fail Record conditions.

Important:

If more than 6 tests have been attempted and the DTC has not passed or failed this key cycle the test may be aborting. Go to diagnostic aids.
5. The test may need to be completed up to 6 times in order to pass or fail.

Does the scan tool indicate the DTC ran and passed this key cycle?


--


System OK


Go to Step 4

4


1. Visually and physically inspect the three-way catalytic converter for damage.
2. Inspect for the following:
* Dents.
* Severe discoloration caused by excessive temperatures.
* Holes.
* Internal rattle caused by damaged catalyst substrate.
3. Also, ensure that the three-way catalytic converter is a proper original equipment manufacturer part.

Did you find damage?


--


Go to step 9


Go to step 5

5


Visually and physically inspect the exhaust system for leaks.

Did you find a problem?


--


Go to Step 7


Go to Step 6

6


Visually inspect for the following:

* Oxygen sensors for damage
* Oxygen sensors wiring harness for damage

Did you find a problem?


--


Go to Step 8


Go to Step 9

7


Repair the exhaust system as necessary.

Did you complete the repair?


--


Go to Step 10


--

8


Replace the oxygen sensor or repair the wiring as necessary. Refer to Heated Oxygen Sensor (HO2S) Replacement or Wiring Repairs in Wiring Systems.

Did you complete the replacement?


--


Go to Step 10


--

9


Notice

In order to avoid damaging the replacement three-way catalytic converter, correct the engine misfire or mechanical fault before replacing the three-way catalytic converter.

Replace the three way catalytic converter. Refer to Catalytic Converter Replacement in Engine Exhaust.

Did you complete the replacement?


--


Go to Step 10


--

10


Important:

If the A/C is left on the following diagnostic may not run.

1. With a scan tool, clear DTCs.
2. Turn OFF the A/C.
3. Fully open the hood.
4. Operate the vehicle within the Fail Record conditions.

Important:

If more than 6 tests have been attempted and the DTC has not passed or failed this key cycle the test may be aborting. Go to Diagnostic Aids.
5. The test may need to be completed up to 6 times in order to pass or fail.

Does the scan tool indicate the DTC ran and passed this key cycle?


--


Go to Step 11


Go to Step 4

11


Does the scan tool indicate any DTCs that you have not diagnosed?


--


Go to applicable DTC


System OK
Document ID# 570323
2000 Chevrolet/Geo Camaro

 

we'll I'm in Michigan and we don't have all the laws like in CA. I got it from a shop around town. Paid 100$ for it and almost 80$ for the labor!!! and it wasn't the direct fit cat. They had to cut the old one and weld the new one!



Man before you jump and spend 800$ to replace it just look around. I'll learned my lesson couple of months ago when a shop wanted 500$ to replace my spark plugs & wires. 500$ for me is kinda a lot for some sparkplugs&wires so I called a couple of places around and I manage to find a shop that did it for 250$(including the parts) and they changed the fuel filter too .

Research Research Research !!!!

 

still did not answer my question rejk