p0170 Fuel Trim Malfunction. What causes it,and how do I fix it.

 

could be one of two thing i think. 1) there is a leak and the cause could be the valve cover gasket or 2) You could have bad air flow through your MAF. Those are just a couple. there may be more. Is this the only code that your getting?

 

yep

 

Check for a manifold vacuum leak somewhere or some other source of unmetered air.

Joel, CA

 

Check your intake piping for cracks or rips, loose clamps. cleanliness of the MAF as well as the air filter. Let us know what you find.

 

also get the cat and the o2 sensors checked(if you still have a cat). faulty readings from bad o2 sensors can make the ECU think that there is a problem with the a/f ratio.

 

wont that ussually throw another code in there too though. Ussually i think you will get the fuel code but you will also get the 02 code for bank 1 or bank 2....right?

 

sometimes, yes. but i know that there is not a code for a bad cat, and it also throws similar codes. when my cat went bad, it threw P0171 and P0174 codes.

 

ok ill agree on the cat but not the o2's being a possible problem. But because its only throwing that one code i am going to still guess a leak