OBD2 Codes
 

Hi, I am new here, but I heard this was a good place to go to get some Info. I need to pin point the problem with my car. I ran a OBD scanner on my car and It spits out these 2 codes
P0170 and P0171
P0170= Fuel Trim malfunction
P0171= System to lean (Bank 1)

Anyone know what the exact problem could be, or could help give a better explanation.
97 Civic dx - no motor mods
Thanks in advance

Re: OBD2 Codes (97Civic)
 

O2 sensor could be one thing.

Re: OBD2 Codes (Spade)
 

pump.

Re: OBD2 Codes
 

bump

1998 Accord 2.3L 4 cyl. with 151k throwing same codes

It also idles rough as if it wants to die at times...more when I come to a complete stop/

Re: OBD2 Codes
 

Re: OBD2 Codes
 

o2 sensors tend not to be the problem . p0171 and p0172 indicates fuel mixture problem either too lean or rich . engine management is taking its readings from lots of sensors all that the o2 sensors are doing is reading the end product after the fuel is burnt. TRY REPLACING ENGINE TEMPRATURE SENSOR FIRST VERY CHEAP TO BUY ,APROX £18-£20 . USUALY THE LIGHT COMES ON AFTER A SHORT DISTANCE THIS INDICATES THAT WHEN THERMOSTAT OPENS AT AROUND 80 degrees , THE COLD RADIATOR COOLANT MEETS THE HOT ENGINE COOLANT AND CAUSES A BAD SENSOR TO SAY I DONT LIKE THIS AND THUS GIVES THE ECU THE WRONG READINGS . THIS IS THE MOST LIKLEY CAUSE OF YOUR TROUBLES .just because temp gauge at dash is working ok does not mean the resistance readings being sent to ecu are ok. try and let us all know

Re: OBD2 Codes
 

locate your primary oxygen sensor(sensor thats closest to the exhaust manifold) check to see if ther is a hairline crack around were the o2 sensor is threaded into. common problem on civic's are cracked manifold/converter assembly.