Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSPONTIAC1991FIREBIRD FORMULA, 5.0 F, STANDARD, M39REPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 17 (ENGINE CONTROLS - TESTS W/CODES - 5.0L TBI)PCM/BCM CODE CHARTSCODE 45, RICH EXHAUST INDICATIONEGR PROBLEM

1991 Pontiac Firebird Formula, 5.0 F, Standard, M39

EGR Problem

1991 Pontiac Firebird Formula, 5.0 F, Standard, M39SECTION EGR Problem

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1992 Pontiac Firebird, 1992 Oldsmobile Custom Cruiser, 1992 Chevrolet Caprice, 1992 Chevrolet Camaro, and 1992 Cadillac Brougham. However, it is still accessible from the selected car via links, so may be relevant.

EGR valve sticking open at idle is usually accompanied by a rough idle and/or stalling.

Also check for shorted or leaking injector and fuel-contaminated oil. If Code 45 is intermittent, see INTERMITTENTS in the TESTS W/O CODES article in this section.

Fig 1: Code 45, Schematic, Rich Exhaust Indication

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.