Question about 2001 Pontiac Grand Prix
I've got a 2002 Grand Prix GTP 3.8L Supercharged V6, nearly the same motor.
I had the exact same problem, misfire on Cyl. 5 and random/multiple misfire.
I replaced all the wires, plugs, coils, and even the ignition module. My next thought was either fuel or exaust.
Replaced my Cat. with a 2.5" ZZP downpipe, and the car ran alot better, but still had a tiny bit of hesitation over 4000rpms.
So i checked all the fuel injectors, and the #5 injector was bad.
To check, get an ohm meter, remove the injector connectors, and contact the 2 posts inside the injector. They should read between 12.4-14 or so.
Mine was at 11.2.
Replaced all the fuel injectors, and she runs like a champ
Posted on Apr 28, 2009
Here is a copy of the "Policy Adjustment" that I took to the dealer with me this morning. Hope this helps any of you.
Subject: Special Policy Adjustment - Catalytic Converter #05551 -(09/14/2005)
Models: 2001-02 CHEVROLET IMPALA, MONTE CARLO
2001-02 PONTIAC GRAND PRIX
2001-02 BUICK REGAL
EQUIPPED WITH 3.4L (RPO LA1 - VIN E) OR 3.8L (RPO L36 - VIN K) V6 ENGINE
Some customers of 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; and Buick Regal model vehicles, equipped with a 3.4L (RPO LA1 - VIN E) or 3.8L (RPO L36 - VIN K) V6 engine, may experience a condition where the vehicle exhaust 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.
Special Policy Adjustment
This special policy covers the condition described above for a period of 10 years or 120,000 miles (190,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. The repairs will be made at no charge to the customer.
For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after September 15, 2005 are covered by this special policy and must be submitted using the labor operation codes provided with this bulletin. Claims with repair orders prior to September 15, 2005 must be submitted to the Service Contract provider.
Involved are all 2001-02 Chevrolet Impala, Monte Carlo; Pontiac Grand Prix; Buick Regal model vehicles, equipped with a 3.4L (RPO LA1 - VIN E) or 3.8L (RPO L36 - VIN K) V6 engine and built within the following VIN breakpoints:
Parts required to complete this special policy are to be obtained from General Motors Service Parts Operations (GMSPO).
Converter, Catalytic (L36 engine)
Converter, Catalytic (LA1 engine)
Gasket, Catalytic Converter (Converter to I-Pipe, both)
Gasket, Exh Manif Pipe (L36)
Gasket, Exh Manif Pip (LA1)
General Motors will notify customers of this special policy on their vehicles (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly).
Catalytic Converter Inspection
Begin the inspection by reviewing the condition described by the customer. Refer to "Description and Operation," SI document 657895, to help you determine the correct symptom diagnostic procedure when a malfunction exists.
Posted on Feb 08, 2009
Check the cap and rotor - if the contact point for cylinder number 5 is worn or corroded, or the edge of the rotor is smooth, you need to change them (the rotor's edge should look like the edge of a quarter, with ridges). If the contact point on the cap is worn out, it won't fire the plug.
There's a chance that the fuel injector for that cylinder isn't firing, so that would be something to look at if the electrical work doesn't fix the problem, but it sounds as if it's more of a problem with the electrical parts than a fuel injector.
Posted on Sep 28, 2008
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