Catalytic Converter Problem

[ontheedge02]

I have a 2001 Buick Regal with 74K miles on it and had been having problems getting it to accelerate. The engine was running smoothly, but it just wouldn't go. I replaced plugs, wires, fuel filter, TPS (had a dead spot), and the fuel pump (was 3psi below spec). After all this, it was still a problem. Did some more testing with my ohm meter and reduced the possibility that it was the coils or fuel injectors.

Just a couple weeks ago, I got a letter saying that the catalytic converters on the 01 thru 05 models were having problems with a cone coming loose and reducing the air flow. Since I was at a loss for the problem, I took it to the dealer to have this checked out and sure enough, that was the deal. All repairs were free.

I am writing this to let others know that if they are experiencing a smooth running engine with little acceleration (it would go highway speed eventually), they should have this checked out. The only drawback is that if it is something else, you will have to pay for the diagnosis. This would have saved me $200 for a fuel pump, since the other stuff needed to be replaced anyways.

I research on this forum occasionally and find it helpful, so hopefully this will help out someone else.

Good Luck with your Buicks!

[katana1981]

maybe thats why my service engine soon light went on the other day but went off after 1 hour of driving...

[BNaylor]

Here's a copy of that letter. Note that the CAT convertor warranty period was extended. And this is not a recall action.

************************************************** *

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.

************************************************** **

[ontheedge02]

I didn't have any SES light or codes in the computer. However, I could hear what I thought was the EGR valve opening and closing as I tried to accelerate. The harder I pushed, the worse it was. However, sometimes if I just held the pedal in one position, it would eventually take off. This made me thing that it wasn't the catalytic converter. Also, it seemed to get worse as it warmed up, but for the most part it was bad cold too.

[katana1981]

btw, if the service engine soon light is off now, i don't have to go to the dealer even though it went on for couple of minutes?!

[BNaylor]

Originally Posted by ontheedge02

I didn't have any SES light or codes in the computer. However, I could hear what I thought was the EGR valve opening and closing as I tried to accelerate. The harder I pushed, the worse it was. However, sometimes if I just held the pedal in one position, it would eventually take off. This made me thing that it wasn't the catalytic converter. Also, it seemed to get worse as it warmed up, but for the most part it was bad cold too.

That is very typical. The problem is when the CAT is clogged there is no guarantee the PCM will trigger the SE/CEL light which makes it even more frustrating.

Some owners did have the following DTC error codes:

P0300 - Mulitiple, random misfire
P0420 - CAT efficiency low
P040X - EGR flow problems

Other symptoms include:

Misfiring when accelerating.

High idle at start up.

Poor acceleration and a cutout at 4000 rpms

Surging acceleration

Engine overheating

Poor fuel economy