P0101
P1573
P0125
P0171
P0172
P0400
P0420
these codes recently came out when i had my comp checked? is anyone familiar with these codes? have u had them come up and how did you fix the problem? any help will be appreciated..thanks

 

P0101= mass air flow circuit, range or performance problem
P0125= insufficient coolant temp for closed loop fuel control
P0171= system to lean,left bank on 4 sensor systems
P0172= system too rich, left bank on 4 sensor systems
P0400= EGR flow fault
P0420= catalyst system efficiency below threshold, left bank P1573????????

 

any thought of what might be causing these codes? how to fix?

 

Do you have any performance loss when driving or is it still the same

 

i have performance loss...feels like fuel loss..really sluggish

 

I would go get your EGR valve checked. That would definetly alter your performance if faulty

 

what exactly does the EGR valve do? whats it for?

 

It's emissions control. You're in Cali. You're fucked, lol.