P CODES (POWERTRAIN) P0400 - P0499

"catalyst System Efficiency Below Threshold (bank 1)". Is This Something I Can Repair Myself? I Have Already Changed Out All Sensors...

I Have This Code Showing Up On My Buick Can You Let Me Know What Types Of Things Can Throw This.

Caty. Conv. Efficiency Low Bank One. The Converter Has Been Replaced And The Code Later Appeared Again. The Oxygen Sensor Was Then Replaced...

Check Engine Light Is On And Need Help With The Location Of The Exhaust Pressure Sensor?

Cars Service Engine Soon Light Is On. Had Codes Read Came Up P0440-evap Small Leak/no Flow Condition, And P0459-evaporative Emission Purge...

I Am Very Familiar With Bmws But Never Seen This Code Before, 93,000 With No Issues All Of A Sudden Two Miles Away From Home And I Get...

Engine Light Came On Although The Car Seems To Be Running Okay. I Was Told By A Mechanic That It Could Be Cooling System Issue; Thermostat...

My Civic Had A Water Pump Pulley Failure, The Pump Hub Broke Off, Which Was Covered By A Recall And Still Under Warranty. I Drove The Car...

Car Is Starting And Running Well But When Stop At The Light The Idle Look Like Something Is Wrong.

These Codes Have Been Coming Up Intermittently For A Year And Stay On For About 100 Miles Then Go Off. The Check Engine Light Is Coming On...