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 MANUALSCHEVROLET1993FORWARD CONTROL 7.4 NREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODES - V8SUMMARYCODE 45, RICH EXHAUST INDICATIONEGR PROBLEM
1993 Chevrolet Forward Control 7.4 N
EGR Problem
1993 Chevrolet Forward Control 7.4 NSECTION EGR Problem
EGR valve sticking open at idle is usually accompanied by a rough idle and/or stalling. If Code 45 is intermittent, see INTERMITTENTS in TESTS W/O CODES article in this section.
CODE 45 ECM TERMINAL & CIRCUIT WIRING IDENTIFICATION
| Application | ECM Terminal | Wire Color | |||
|---|---|---|---|---|---|
| All With 4L80-E Transmission (1) | |||||
| Oxygen Sensor Signal | C14 | Purple | |||
| Oxygen Sensor Ground | C13 | Tan | |||
| 2.5L, 2.8L, 3.1L & "C", "K" & "P" Series 4.3L (1) & V8 (All With M/T) | |||||
| Oxygen Sensor Signal | D7 | Purple | |||
| Oxygen Sensor Ground | D6 | Tan | |||
|
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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.