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2006 Dodge Grand Caravan 3.8L P0506 Fault: Gas Smell, Poor Idle, Vacuum Leak Suspected?

Model: caravan 2006 Fault Code: P0506 Posted: 2017-01-02 13:45

Hi there, I'm seeking help with my 2006 Dodge Grand Caravan 3.8L (Innova 3130E) that's showing a Generic Pending P0506 code (1/1) on the OBD-II scan tool. Live data shows STFT B1 between 25% and 32%, with O2 B1S1 readings from 0.3 to 0.76, and O2 B1S2 around 0.65 to 0.7. Before starting the engine, the MAP sensor reads approximately 29 inHg; once running, it drops to about 14 inHg at idle. I can clearly smell gasoline coming from the exhaust pipe tailpipe. The idle is rough—like a train—and the engine occasionally stalls at stop signs or red lights. What could be causing this? Is it due to a vacuum leak or a dirty throttle body? Thanks for any insight! Vehicle: 2006 Dodge Grand Caravan 3.8L (Innova 3130E) Fault Code: P0506

Related fault codes
P0506
Comments (3)
Anonymous 2017-01-02 14:12

Please provide vehicle history — any air filter replacements, modifications, or other stored diagnostic codes? Check for vacuum leaks. A clean throttle body using a dedicated throttle body cleaner is often effective. Verify that the throttle plate is fully closing — this may not apply if equipped with electronic throttle (fly-by-wire). Also check fuel pressure. What is the voltage reading on B2S1? (Note: This sensor may not be available on all scan tools.)

Anonymous 2017-01-02 14:38

I don't have any other stored codes. There's no B2S1 sensor in my scan tool. If there’s a vacuum leak, shouldn’t the MAP sensor reading drop significantly? My understanding is that a normal vacuum range would be 29 to 14 inHg — a difference of 15 inHg — which seems reasonable. However, I’ve used a propane torch for testing and haven't found any leaks (possibly due to limited skill or technique). I've also checked ignition coils and fuel system components. No issues found so far. Could the gas smell be caused by a dirty throttle body? My current theory: High STFT and high O2 readings suggest possible fuel injector problems — is that accurate? Many thanks for your help!

Anonymous 2017-01-02 14:58

Quick, actionable points: - No other diagnostic codes present. Is the engine reaching operating temperature (~210°F)? The scanner should show this. - STFT is elevated — a clear sign of fuel trim issues. - Air filter or restriction? Avoid using K&N oil-coated filters as they can cause problems. - Possible causes: vacuum leaks, low fuel pressure, clogged injectors. Check fuel pressure and perform a KOEO (Key On Engine Off) test to observe any drop in pressure. Also inspect: - PCV system - IAC motor passages - Vacuum lines for leaks - Air intake system - Throttle body and throttle linkage