2000 Mitsubishi Galant CODES!! HELP

[JAM25]

My aunt has a 2000 Mitsubishi Galant ES 2.4 L engine.

The Car has 224K miles and running like a beauty.

It has 2 codes I need feedback on if you guys have experience on these codes.

The Codes are:

P0170
&
P0420

Any ideas on where to begin to fix these two codes.

 

[zzyzzx]

http://www.obd-codes.com/p0420
http://www.obd-codes.com/p0170

If is still has the original O2 sensors, replace all of them. Also check for exhaust leaks and vacuum leaks.

 

[Chris142]

420 is 99% of the time a cat thats not working correctly. The 170 is fuel id start by testing pressure and volume

 

[clinebarger]

Agreed, A P0420 is 99% of the time a faulty converter..

P0170 code only means there is some kind of a air/fuel mixture problem, it is not specific. Check the fuel trim information to determine if the car is running rich or lean. Positive numbers on the long term fuel trim indicate the system is adding fuel due to a lean condition. Negative numbers mean the system is removing fuel due to a rich condition. Or a "smoking gun" like a vacuum leak, low fuel pressure, Or faulty pressure regulator.

 

[javacontour]

Or burning some other hydrocarbon. Does it burn oil?

 

[Merkava_4]

P0420 is the result of having P0170.