My check engine light came on yesterday. Scanner revealed the following two codes: P0170 and P0172 (Fuel trim malfunction and running too rich).

Any ideas???

 

Your powertrain control modual has sent you these mesages because it has recognizes a too rich or to lean on your car..

Check the o2 sensor, it's more than likely defective or has a loose plug.

Could also be a fuel injector problem, check it with a gage.

And here is the bigger one..when 2 codes go off at once...Get ready to buy yourself a Maf or Mass Airflow Sensor..take it off and take it to AutoZone, they can check it for you.

Let us know if that was the problem..

WheelBrokerAng

 

By the way!
This goes into the Gen Tech forum..has nothin to do with DIY

I moved it to here for ya!

 

I changed the O2 sensor in May 2009 and the car has been fine until now.

Looking back at the service records, Honda dealer had changed the Fuel Pressure Regulator back in 2003 and once again in 2004.

Do Accords have an Mass Air Flow sensor? If so, where is it located? I would like to have it tested as you suggested

 

What year, model, transmission... accord do you have? Put it in your signature so we can always see it.

 

Just updated signature. My car in question is a 1998 Accord LX-A automatic.

 

Generic scanners...... Sheeeeesh.
They will report a code as close as possible to the Manufacturer code, so you can have a generic scan toll crying out "Fuel Trim Malfunction" and the Real problem could be the EGR valve.
You need to watch the O2 sensor reading to be sure of the real problem.
if indeed it is running rich,I'd say to do a fuel pressure leakdown check.
Be sure you don't have an injector leaking thru.