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The HEGO is sensitive to silicone based
products and can become contaminated.
Avoid using silicone sealers/lubricants on
any fuel or exhaust related components.
10. Reconnect negative battery cable.
11. Turn key to ON.
12. Check for leaks. If leaks are detected, make
repairs.
XXV. LPG FUEL SYSTEM LEAK TEST
1. Use a commercially available liquid leak detec-
tor or an electronic leak detector and follow the
manufacturer’s instructions.
IMPORTANT
When using both methods, use the electronic leak
detector
fi
rst to avoid contamination by the liquid
leak detector.
XXVI. RESTRICTED EXHAUST SYSTEM
DIAGNOSIS
PROCEDURE:
1. Stop Engine. Carefully remove the HEGO.
2. Install Exhaust Back Pressure Test Gauge
(J35314-A) in place of the HEGO.
3. With the engine idling at normal operating
temperature, observe the exhaust system
back pressure reading on the gauge. Reading
should not exceed 8.6 kPa (1.25 psi).
4. Increase engine speed to 2000 RPM and ob-
serve gauge. Reading should not exceed
20.7 kPa (3 psi).
5. If the back pressure at either speed exceeds
speci
fi
cation, a restricted exhaust system is
indicated.
6. Inspect the entire exhaust system for a col-
lapsed pipe, heat distress or possible internal
catalytic converter failure.
7. If there are no obvious reasons for the exces-
sive back pressure, the catalytic converter is
likely damaged and should be replaced.
8. Check for MIL. If a DTC code is found, refer
to the Electrical Section for further diagnosis.
1. Back Pressure Gauge
2. Heated Exhaust Gas Oxygen Sensor
(HEGO 1--Sensor between the engine and
catalytic converter).
3. Exhaust Pipe/Muffler
Exhaust Back Pressure Test
XXVII. CATALYTIC CONVERTER
REMOVAL PROCEDURE
1. Remove the Catalytic Converter using the
OEM end product processes
INSTALLATION PROCEDURE
IMPORTANT
The Catalytic Converter is speci
fi
cally designed to
meet the emission control of the certi
fi
ed engine.
Use only the OEM speci
fi
ed part. Install the Cata-
lytic Converter using the OEM end product
processes.
1. Start engine
2. Check for any DTC codes and clear
3. Verify engine is in closed loop and no MIL
lights are present.
4. If a DTC code is found, refer to the Electrical
Section for further diagnosis.
Summary of Contents for 3.0L GM
Page 4: ...4 ...
Page 5: ...5 General Information ...
Page 9: ...9 Maintenance ...
Page 16: ...16 ...
Page 17: ...17 LPG Fuel System ...
Page 18: ...18 LPG FUEL SYSTEM OPERATION ...
Page 25: ...25 LPG Closed Loop Schematic ...
Page 26: ...26 ...
Page 27: ...27 LPG System Diagnosis ...
Page 35: ...35 Fuel Symptom Diagnostics ...
Page 51: ...51 Electrical Section ...
Page 52: ...52 ...
Page 53: ...53 DST Diagnostic Scan Tool ...
Page 59: ...59 Select the USB button then click the OK box Click on the Search attached device box ...
Page 67: ...67 When connected the live data stream appears in the Value column ...
Page 78: ...78 ...
Page 80: ...80 ...
Page 81: ...81 Engine Wire Schematic ...
Page 82: ...82 2011 3 0L GM Engine IMPCO Emission Certified LPG Fuel System ...
Page 83: ...83 ...
Page 84: ...84 ...
Page 85: ...85 Engine Wire Harness Repair ...
Page 89: ...89 Diagnostic Trouble Codes DTCs ...
Page 93: ...93 ...
Page 101: ...101 ...
Page 105: ...105 ...
Page 109: ...109 ...
Page 119: ...119 ...
Page 129: ...129 ...
Page 133: ...133 ...
Page 137: ...137 ...
Page 141: ...141 ...
Page 145: ...145 ...
Page 161: ...161 ...
Page 165: ...165 ...
Page 169: ...169 ...
Page 173: ...173 ...
Page 201: ...201 ...
Page 209: ...209 ...
Page 213: ...213 ...
Page 217: ...217 ...
Page 221: ...221 ...
Page 225: ...225 ...
Page 229: ...229 ...
Page 237: ...237 Servicing the Fuel System ...
Page 254: ...254 ...
Page 255: ...255 LPG Parts Diagram ...
Page 256: ...256 THROTTLE BODY ASSEMBLY ...
Page 258: ...258 FUEL RAIL INJECTORS ...
Page 260: ...260 REGULATOR ASSEMBLY ...
Page 262: ...262 HOSE ASSEMBLIES COOLANT VACUUM FUEL ...
Page 264: ...264 THERMOSTAT HOUSING ...
Page 266: ...266 ENGINE CONTROL MODULE ...
Page 267: ...267 ENGINE CONTROL MODULE Item Description Qty IMPCO Part Number 1 ECM Liugong 1 A11 173 ...
Page 268: ...268 SENSORS 4 1 3 6 5 2 7 ...
Page 270: ...270 DISTRIBUTOR ...
Page 272: ...272 FUSE BOX BRACKET ...
Page 274: ...274 IGNITION COIL ...
Page 275: ...275 IGNITION COIL Item Description Qty Part Number 1 Coil Ignition 1 7245530 ...
Page 276: ...276 MANIFOLDS ...
Page 278: ...278 WIRE HARNESS FUSES FUSE BOX COVER Fuse Box Layout 4 ...
Page 280: ...280 PCV VENT VALVE ...
Page 282: ...282 MISCELLANEOUS ENGINE ...
Page 284: ...284 ALTERNATOR ...
Page 286: ...286 STARTER ...
Page 291: ...291 ...
Page 292: ...292 3 0L UPPER ...
Page 294: ...294 3 0L LOWER ...
Page 298: ...298 ...
Page 299: ...299 Labor Time Guide ...
Page 317: ...317 Definitions ...
Page 322: ...322 ...
Page 323: ...323 Appendix ...
Page 327: ...327 DTC SPN FMI Chart ...