Traditional gasoline car fault

Search fault code and browse forum case posts.

This page is designed for quick diagnosis on gasoline vehicles by combining code lookup with real discussion cases. Enter a fault code to filter related topics, then compare symptom context such as cold start behavior, acceleration load, fuel-trim deviation, ignition misfire pattern, and recent maintenance history. Many codes can be triggered by shared root causes, so use cross-checks from multiple posts before replacing sensors, coils, injectors, or catalytic components.

Forum post list 12644 total topics
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P0174 Code and Rough Idle in 1994 Ford Cougar XR-7 with V8 Engine

Hi! I'm experiencing a P0174 diagnostic trouble code (system too lean on bank 2) on my brother's 1994 Ford Cougar XR-7 equipped with the large V8 engine. This issue is accompani...

ol' | P0174
2007-07-28
2 comments
M

2000 Mazda Protege P0171 and P0442 Diagnosis: How to Fix Lean Mix & EVAP Leak at 150,000 km

I own a 2000 Mazda Protege with a 1.6L engine and 5-speed manual transmission, currently at 150,000 kilometers. The vehicle is displaying OBD-II diagnostic codes P0171 (System T...

Mazda Protege 2000 | P0171
2007-07-28
15 comments
2

P0420 Diagnostic and Repair for 2001 Chevrolet S10 2WD with Starting Issues and Brake Light Problems

I own a 2001 Chevrolet S10 2WD with a 2.2L engine. The check engine light has been on for approximately one year, and the fault code displayed is P0420. About 8 out of 10 times ...

2001 S10 | P0420
2007-07-27
3 comments
2

2002 Hyundai Sonata P0340 Fault: Diagnosis and Common Fixes After Timing Belt Replacement

My 2002 Hyundai Sonata (2.4L MFI DOHC engine) has developed a P0340 fault at around 105,000 miles. The car runs smoothly when cold but begins to misfire and lose power after war...

2002 Hyundai Sonata | P0340
2007-07-27
14 comments
2

P0300 Misfire on 2002 VW Passat: Cold Start Only, Cylinders 1 & 2 Affected

I'm experiencing a P0300 (multiple cylinder misfire detected) code on my 2002 1.8L VW Passat. The only noticeable symptom is that when I start the car after it has sat for 8+ ho...

2002 VW Passat | P0300
2007-07-27
6 comments
2

2000 Volkswagen Beetle P1176 Code: Rear O2 Sensor Correction Limit Exceeded - MAF Sensor Diagnosis

My 2000 Volkswagen Beetle has been showing a check engine light with fault code P1176. AutoZone's breakdown indicates the issue is related to the rear oxygen sensor's correction...

2000 Volkswagen Beetle | P1176
2007-07-26
5 comments
1

1999 3.4L V6 Grand Am, DTC P0440

DTC P0440 - Evaporative Emission (EVAP) System Conditions for setting the DTC: The EVAP system is not able to achieve or maintain vacuum during the diagnostic test. The fuel pum...

1999 3.4L V6 Grand Am | P0440
2007-07-25
13 comments
9

P0100, P0325, and P0304 Fault Codes on 1997 Nissan Altima: Causes and Fixes

I own a 1997 Nissan Altima with nearly 200,000 miles. The vehicle has historically been reliable but now exhibits sputtering, hesitation, and occasional stalling at low RPMs. Th...

97' Nissan Altima | P0100
2007-07-24
6 comments
1

P0171 Fault in 1997 Dakota 5.2L V8 with Automatic Transmission - Intake or Vacuum Leak Diagnosis?

I recently started experiencing engine jerking and a significant drop in fuel mileage after several hours of towing my trailer. This only occurs during extended use, and I've no...

1997 Dakota | P0171
2007-07-24
8 comments
1

1998 Dodge Intrepid P1297 and P0300 Fault: Fuel Pressure Diagnosis and Tool Requirements

Thanks for the helpful tip, Jeff. I'm now looking to install a fuel pressure gauge on my 1998 Dodge Intrepid to help diagnose the recurring P1297 and P0300 codes. As advised, I ...

1998 Intrepid | P0300
2007-07-24
7 comments
2

P0171 and P0174 Fault Diagnosis for 2001 V6 3.8L Camaro - Vacuum System Issue?

Some suggest replacing the brake booster and check valve as part of the vacuum system to resolve the P0171 and P0174 lean mixture codes in my 2001 V6 3.8L Camaro. While this may...

2001 V6 3.8 Camaro | P0171
2007-07-24
2 comments
M

P0340 Fault in 1999 Mercury Villager: Cam Sensor Issue and Hot-Engine Symptoms

I own a 1999 Mercury Villager with 171,000 miles and has been well maintained. The vehicle is throwing fault code P0340, indicating a camshaft position sensor malfunction. The i...

Mercury Villager | P0340
2007-07-24
9 comments
9

Error Code P1550 on 96 Nissan Sentra

1996 Nissan Sentra, 60k miles, 4 cylinder. My car's check engine light came on so I plugged in an OBD-II reader and it reports P1550 (TCC Solenoid Valve). What and where is the ...

96 Nissan Sentra | P1550
2007-07-23
2 comments
9

1998 Ford Explorer 5.0L V8 Misfire & OBD2 Codes P0401, P0405, P1309 - Diagnosis and Fixes

I own a 1998 Ford Explorer with a 5.0L V8 engine, 2WD, and am experiencing persistent misfire issues, most noticeable at idle, along with a significant drop in fuel efficiency. ...

98 Ford Explorer | P0401
2007-07-23
7 comments
1

1998 Intrepid P1297, P0300

I have a 1998 Chrysler Intrepid with a 2.7 that has started giving me the P0300 fault code (multiple cylinder misfire) and code 1297 (MAP sensor doesn't change its reading when ...

1998 Intrepid | P0300
2007-07-23
19 comments
2

P0171 and P0174 2001 V6 3.8 Camaro

I have replaced the fuel injectors, fuel filter, spark plugs, air filter and the fuel pump. Now that all that is out of the way here is my problem. First I started getting a P0...

2001 V6 3.8 Camaro | P0171
2007-07-23
19 comments
9

1997 GMC Safari Multiple O2 Sensor Codes P0134, P0135, P0146, P0147, P0300 - What to Do?

I own a 1997 GMC Safari that runs smoothly and has recently had spark plugs, wires, cap, and rotor replaced at 100,000 miles. During an emissions inspection, I received several ...

97 Safari | P0134
2007-07-21
1 comments
9

P0300 Fault on 1996 Buick LeSabre 3.8L: Possible Electrical Link to Horn Issue?

My 1996 Buick LeSabre with a 3.8L engine is showing a P0300 random misfire code, and it has accumulated 135,000 miles. Last week, the horn unexpectedly activated at around 2:00 ...

96 Buick LeSabre 3.8 | P0300
2007-07-21
3 comments
2

2001 Subaru Outback 4-Cylinder P0328 Knock Sensor #1 Signal High - Diagnosis and Fixes

Hi everyone, I'm having an issue with my 2001 Subaru Outback 4-cylinder. The check engine light is flashing intermittently, and my OBD2 scanner shows a persistent P0328 code: 'K...

2001 | P0328
2007-07-21
1 comments
9

1998 BMW 323i P0170 and P0188 Fault Diagnosis - Fuel Trim & Fuel Temperature Sensor Issues

Hello everyone! This is my first time posting on the forum, so I'm hoping to get some clear guidance. I own a 1998 BMW 323i with a 6-cylinder engine and 5-speed manual transmiss...

98 BMW 323i | P0170
2007-07-21
2 comments
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Practical workflow for fault-code troubleshooting

Start by confirming battery voltage and reading freeze-frame data, then inspect wiring and connectors before replacing parts. If the code returns after clearing, record the exact driving or idling condition when it reappears. Prefer case threads with complete repair feedback, because confirmed outcomes provide stronger guidance than one-time symptom descriptions. Following a step-by-step workflow reduces repeated repairs and lowers total diagnosis time.