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AP Exhaust 645288 Catalytic Converter
Direct-Fit Catalytic Converter for GM Full-Size Sedans
AP Exhaust 645288 is a Federal / EPA direct-fit catalytic converter built for OE-style replacement on select Buick, Cadillac, and Pontiac applications. It uses a stainless steel body with a ceramic substrate and is built to OE dimensions for proper fitment on the listed vehicles.
Compatible With 1997-2005 Buick Park Avenue, 2000-2005 Buick LeSabre, 2000-2005 Cadillac DeVille, and 2000-2005 Pontiac Bonneville applications, this converter is a practical choice when replacing a worn or restricted emissions component. AP Exhaust 645288 is engineered for direct-fit installation on the listed exhaust layouts, including configurations that require cutting or aftermarket pipe adaptation.
Key Features
- Federal / EPA direct-fit catalytic converter
- Stainless steel body for corrosion resistance
- Ceramic substrate material
- 4-bolt welded flange inlet
- 2.57" OD pipe outlet
- Overall length: 20 inches
- Inlet gasket included; outlet gasket not required
- No O2 sensor ports
Fitment Details
- Fits 2000-2005 Buick LeSabre, N/A β Direct Fit; Conv. Only; Cut as required; Federal and California Emissions; Single Exhaust.
- Fits 2000-2005 Buick LeSabre, N/A β Direct Fit; Federal and California Emissions.
- Fits 1997-2005 Buick Park Avenue, N/A β Direct Fit; 00-05; Federal and California Emissions; Cut as required.
- Fits 2000-2005 Buick Park Avenue, N/A β Direct Fit; For use with aftermarket pipes; additional sizing, bushings, and cutting may be required; Federal and California Emissions.
- Fits 2000-2005 Cadillac DeVille, N/A β Direct Fit; Use with aftermarket center pipe; OE system was a welded assembly; cut as required; Federal and California Emissions; Dual Exhaust, chrome tip applications.
- Fits 2000-2005 Cadillac DeVille, N/A β Direct Fit; For use with aftermarket pipes; additional sizing, bushings, and cutting may be required; Federal and California Emissions.
- Fits 2000-2005 Pontiac Bonneville, N/A β Direct Fit; Use with aftermarket components; cut as required; Federal and California Emissions; Single Exhaust.
- Fits 2000-2005 Pontiac Bonneville, N/A β Direct Fit; For use with aftermarket pipes; additional sizing, bushings, and cutting may be required; Federal and California Emissions.
What This Converter Helps Address
- Failed emissions testing caused by a worn catalytic converter
- Restricted exhaust flow from a deteriorated substrate
- Check engine light concerns related to converter efficiency
- Exhaust leaks at the converter connection points
- Fitment issues when replacing an OE welded assembly with serviceable parts
Installation Notes and Tips
Review the vehicle-specific notes before installation, since some applications require cutting, aftermarket center pipes, or additional sizing and bushings. This part uses a 4-bolt welded flange inlet and a 2.57" OD pipe outlet, so confirm the exhaust connection style before ordering. For Cadillac DeVille applications, the OE system was a welded assembly and replacement of related exhaust components may be required for proper service fit.
This part cross-references Monroe Shocks & Struts (e.g., 172286, 182286) for the same application.
Quality Assurance
AP Exhaust uses proprietary substrate chemistry and advanced manufacturing processes, including automated workstations, spinner welding equipment, and high-speed production lines, to build converters to exact OE dimensions and fitment. That production approach supports consistent construction and competitive replacement value for the listed Buick, Cadillac, and Pontiac applications.
| Brand | AP Exhaust |
| Part Number | 645288 |
| Body Material | Stainless steel |
| Inlet Gasket | Yes |
| Inlet Hardware | None |
| Inlet Type A | 4 bolt welded flange |
| O2 Sensor Ports | None |
| Outlet Gasket | Not required |
| Outlet Hardware | None |
| Outlet Type A | 2.57" od pipe |
| Overall Length (IN) | 20 |
| Substrate Material | Ceramic |
| Type | Federal / epa direct-fit |
This part fits 51 vehicles. Search below:
| Year | Make | Model | Liters | Cylinders | Position | Notes |
|---|---|---|---|---|---|---|
| 2005 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; (Conv. Only); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2005 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2005 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 2005 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2005 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; (Use w/ Aftermarket Center Pipe); OE system was a welded assembly. It is recommended that all parts noted [1] should be replaced.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required.; Dual Exhaust, chrome tip applications |
| 2005 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2005 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; (Use With Aftermarket Components); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2005 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2004 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; (Conv. Only); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2004 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2004 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 2004 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2004 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; (Use w/ Aftermarket Center Pipe); OE system was a welded assembly. It is recommended that all parts noted [1] should be replaced.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required.; Dual Exhaust, chrome tip applications |
| 2004 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2004 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; (Use With Aftermarket Components); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2004 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2003 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; (Conv. Only); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2003 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2003 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 2003 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2003 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; (Use w/ Aftermarket Center Pipe); OE system was a welded assembly. It is recommended that all parts noted [1] should be replaced.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required.; Dual Exhaust, chrome tip applications |
| 2003 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2003 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; (Use With Aftermarket Components); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2003 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2002 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; (Conv. Only); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2002 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2002 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 2002 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2002 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; (Use w/ Aftermarket Center Pipe); OE system was a welded assembly. It is recommended that all parts noted [1] should be replaced.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required.; Dual Exhaust, chrome tip applications |
| 2002 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2002 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; (Use With Aftermarket Components); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2002 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2001 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; (Conv. Only); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2001 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2001 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 2001 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2001 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; (Use w/ Aftermarket Center Pipe); OE system was a welded assembly. It is recommended that all parts noted [1] should be replaced.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required.; Dual Exhaust, chrome tip applications |
| 2001 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2001 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; (Use With Aftermarket Components); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2001 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2000 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; (Conv. Only); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2000 | Buick | LeSabre | 3.8L | V6 | N/A | Direct Fit; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2000 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 2000 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2000 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; (Use w/ Aftermarket Center Pipe); OE system was a welded assembly. It is recommended that all parts noted [1] should be replaced.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required.; Dual Exhaust, chrome tip applications |
| 2000 | Cadillac | DeVille | 4.6L | V8 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 2000 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; (Use With Aftermarket Components); Cut as required.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Single Exhaust |
| 2000 | Pontiac | Bonneville | 3.8L | V6 | N/A | Direct Fit; For use with Aftermarket pipes, additional sizing, bushings, cutting may be required due to OE exhaust design.; Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details. |
| 1999 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 1998 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
| 1997 | Buick | Park Avenue | 3.8L | V6 | N/A | Direct Fit; (00-05); Federal and California Emissions. Not For Sale or Use on vehicles licensed in the state of CA, CO, ME & NY. Restrictions may apply in other states. Check with your state authority for details.; Cut as required. |
* Always verify fitment with your vehicle's VIN if unsure. Submodel & trim restrictions may apply.