'00 Civic threw this code - P0172. Any thoughts on what to check?

Thanks.

 

What's the code actually for?

 

Fuel trim problem..

If you have a fuel pressure regulator, take it off.. If you have a AFC, Set it to "0"..

basically the ECU cannot completely control the ammount of fuel being given to the engine, either because fuel pressure is too high from a kinked return line in the engine compartment, or under the car.. or POSSIBLY a bad O2 sensor sometimes has that affect..

Check for defects in the fuel return line if everything is stock, and if your O2 sensor has alot of mileage on it, it'd probably be a good idea to replace it.. Especially if you've used race fuel at one time or another..

 

Thanks Gadget for the reply. The fuel line looks OK and I don't have a regulator, so I'm guessing it's the O2 sensor. The car has 139k on it.

BTW what's an AFC?

 

it's an electronic piggyback device that hacks the signals going to the ECU that allows you to change the normal fuel/Vtec settings from stock.. It basically fools the ECU into operating differently..

It's a piece of crap and HIGHLY reccomend against using one.. nothing beats a couple hundred bucks on a dyno tune..