2001 buick regal v6 ls po420 code

within the last 6 months the cat. converter went out on my buick, I got it replaced due to a recall a couple of months later the check engine light came on, I went and got the codes pulled and they told me that it was the bank 1 O2 sensor so I replaced it about 2 weeks later the check engine light came back on took it to get the codes pulled at auto zone and it gave me the
po420 code and the guy that I talked to didn't seem to know what he was thaking aboutl and he asked another man whitch told be that it was the O2 sensor I told him that I already replaced the bank 1 sensor so told me to replace the bank 2 o2 sensor did that, a week later light back on with same same code. anyone with any Ideas??????????????????


thanks
stan

Since you have a 2001 Regal take it back to a dealer and have them replace the CAT convertor under the extended CAT convertor warranty. As long as you have under 120K miles or 10 years, whichever comes first you should be able to get another replacement.

It is well known that CATs on 2001 - 2002 models were flaky. What is to say the replacement installed isn't flaky too. Based on my experiences with a DTC error code of P0420, it is the CAT convertor.

Cat warranty is 8 years or 80K miles unless you are covered by the special policy on certain car lines. if your cat was replaced by a GM dealer less than 12 months or 12K miles it is covered by a parts defect warranty. either way take it to the dealer and have them replace it under warranty.

While at the dealer have them check to see if their is a PCM update that addresses this problem

I received this notice from GM on my '01 Regal GS about 3 months ago. I keep it in the glove box just in case. The GM Technical Service bulletin number is 05551 dated 9/14/ 2005.



************************************************** ******
This is a special policy that raises warranty coverages on the converter in case you experience a failure.

Dear General Motors Customer:

As the owner of a 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; or Buick Regal model vehicle, equipped with a 3.4L or 3.8L V6 engine, your satisfaction with our product is very important to us.

This letter is intended to make you aware that some 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; and Buick Regal model vehicles, equipped with a 3.4L or 3.8L V6 engine, may have a condition where the catalytic converter is replaced due to complaints of lack of power or illumination of the Malfunction Indicator Lamp (MIL). This may be due to the front endcone insulation from the catalytic converter breaking away and blocking the front of the first catalyst brick and preventing the free flow of exhaust gas through the converter.

This is not a recall. Do not take your vehicle to your GM dealer as a result of this letter unless you believe that your vehicle has the condition as described above.

What We Have Done
General Motors is providing owners with additional protection for the Catalytic Converter. If this condition occurs on your 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; or Buick Regal model vehicle, equipped with a 3.4L or 3.8L V6 engine, within 10 years of the date your vehicle was originally placed in service or 120,000 miles (190,000 km), whichever occurs first, the condition will be repaired for you at no charge .

What You Should Do
Repairs and adjustments qualifying under this special coverage must be performed by a General Motors dealer. You may want to call the service department at your dealer to find out how long they will need to have your vehicle so that you may schedule the appointment at a time that is convenient for you. This will also allow your dealer to order parts if they are not already in stock. Keep this letter with your other important glove box literature for future reference.