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.
P0300 Misfire 2002 2500HD 6.0 Please Help
I have been trying to solve my misfire problem and could use some help. I set the sel off every time i get up between 60-75mph no other times. I have attached my scan during an ...
2002 2500HD 6.0 | P03001998 Chevy 1500 V6 with P0306 and P0420: How to Fix Without Major Repairs or Emissions Modifications?
I've been researching similar threads and am looking for practical, low-cost solutions for my 1998 Chevrolet 1500 V6 with persistent fault codes P0306 and P0420. I'm trying to s...
1998 Chevy 1500 V6 | P030697 Chevrolet Silverado with P0141 and P0161 O2 Sensor Fault Codes
My 'Service Engine Soon' light has come on. Using a diagnostic code reader, I've identified trouble codes P0141 and P0160. These codes are typically associated with oxygen (O2) ...
97 Chevy Silverado | P01412008 Mazda 3 P0421 Code: Warm-Up Catalyst Efficiency Below Normal at 40K Miles
I've been experiencing an intermittent check engine light on my 2008 Mazda 3, which Autozone has diagnosed with fault code P0421 — 'Warm-up Catalyst Efficiency Below Normal'. T...
2008 Mazda 3 | P04212004 Chevrolet Silverado 4.8L with P0300 and P0135 Codes After O2 Sensor and Catalytic Converter Replacement
My 2004 Chevrolet Silverado with a 4.8L engine has reached 120,000 miles. Recently, I had both the catalytic converter and oxygen (O2) sensors replaced. Approximately 100 miles ...
2004 Silverado | P0135P0420 Fault Diagnosis and Repair Advice for 1996 Ford Bronco 5.0L with 5-Speed Transmission
Hi everyone, I'm currently dealing with a P0420 diagnostic code on my 1996 Ford Bronco equipped with a 5.0L V8 engine and 5-speed manual transmission. The code indicates 'Cataly...
1996 Bronco 5.0 | P04202004 GMC Denali with P0141 and P0161 After O2 Sensor Replacement - Diagnosis and Fixes
I recently replaced the O2 sensor on my 2004 GMC Denali due to a persistent P0161 fault code. After the replacement, the Check Engine Light turned off. However, just 20 miles la...
04 GMC Denali | P01411997 Jeep Grand Cherokee P0420 Code: Causes and Sensor Replacement Guidance
I own a 1997 Jeep Grand Cherokee with a 5.2L engine and am currently experiencing a persistent P042-0 diagnostic trouble code (DTC). Despite replacing the catalytic converter (C...
1997 Jeep Grand Cherokee | P0420PO442 Diagnostic: Small Evaporative Leak Detected in 2000 Saturn SL2
Hi, I'm experiencing a PO442 fault code on my 2000 Saturn SL2 with a DOHC engine. The issue started about a month ago. I initially replaced the fuel cap with the original GM fac...
Unknown | P04421997 GMC 1500 5.7L Misfire Cylinder 5 - Persistent Issue After Multiple Tune-Ups
I own a 1997 GMC 1500 pickup with a 5.7L V8 engine and 4WD automatic transmission. I've been experiencing a consistent misfire in cylinder 5. During driving, the engine shakes n...
97 GMC 5.7L | P03051999 VW Passat V6 P0431 - Warm Up Catalyst Efficiency Below Threshold (Bank 2) After Replacing Catalytic Converter
I'm having trouble with a persistent P0431 fault code on my 1999 VW Passat V6. I recently replaced the catalytic converter at a local muffler shop, but the code returned after i...
99VW | P04312003 Ford Taurus SES P0171 & P0174 codes (no real symptoms)
2003 ford taurus ses, 47,000 miles history: recently had an oil change, tire rotation, air filter replacement about a week later, i found water on my passenger floor (after it w...
2003 Ford Taurus SES | P01711995 Buick Riviera with 4L60E Transmission: Persistent P0740 Code After Rebuild and Cooler Installation
I'm facing a puzzling issue on a 1995 Buick Riviera equipped with the 4L60E transmission. The vehicle has repeatedly shown a P0740 code — indicating a TCC (Torque Converter Clut...
1995 Buick Riviera | P0740P0446 Fault on 1998 Lexus GS400: Causes, Repair Cost, and Vehicle Operability
Hi everyone, I recently purchased a used 1998 Lexus GS400 with 235,000 miles about a week ago. One day after refueling, the Malfunction Indicator Lamp (MIL) came on. I visited ...
1998 GS400 LEXUS | P0446Fuel Injector Circuit Open Diagnosis: 1999 Dodge Durango with White Smoke and Gasoline Odor
I'm experiencing white smoke exiting my exhaust system with a strong gasoline smell. I've already replaced all spark plugs and the #6 fuel injector. When testing the injector ci...
99 Durango | P21771999 Dodge Ram PO138 O2 Sensor Fault: Can Cleaning Fix It or Must It Be Replaced?
I've heard that cleaning an oxygen (O2) sensor can sometimes avoid the need for replacement. Is this a viable solution for a 1999 Dodge Ram with a PO138 code? Does cleaning actu...
1999 Dodge Ram | P01382006 Jeep TJ SE 2.4L Frequently Throws P0171 Code After Switching to Stock Intake - Diagnosis & Fixes
I recently discovered this forum and am impressed by the structure and community focus. I'm hoping someone can help me troubleshoot a recurring issue with my 2006 Jeep TJ SE 2.4...
06 Jeep TJ SE 2.4l | P01712003 Chevrolet Trailblazer V6 EXT P0014 Fault: Diagnosis and Fix
While driving to work, the SES (Service Engine Soon) light illuminated. A diagnostic test performed via OnStar revealed fault code P0014. Does anyone know how to resolve this is...
03 Trailblazer V6 EXT | P00142007 Toyota Corolla P0607 Code: Causes, Symptoms & PCM Failure Diagnosis
Hello everyone, I'm new here and recently came across this forum through a friend. I currently own a 2007 Toyota Corolla that's been throwing several random OBD-II diagnostic co...
2007 Corolla | P0607Practical 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.