I keep getting lean codes on a stock terminator with 79k. Why???

[Evilspyderman]

Every other day or so I get codes the that say bank one and two lean. What would cause this on a bone stock terminator with 79k miles? Nothing noticeable has changed with the way the engine is running or acting while driving. The exhaust still smells normal so I'm thinking it might be a O2 sensor problem. What does everyone think?

 

[red91stang13]

I would check for a vacuum leak. Most of the time if a car throws that code its because of a vacuum leak.

 

[mu22stang]

Every other day or so I get codes the that say bank one and two lean. What would cause this on a bone stock terminator with 79k miles? Nothing noticeable has changed with the way the engine is running or acting while driving. The exhaust still smells normal so I'm thinking it might be a O2 sensor problem. What does everyone think?

Check/change your fuel filter. Also, clean the fuel rails and the injectors. The stealership has a very concentrated fuel system cleaner they run through it if you don't have the correct tools and/or cleaning agents. Unplug your battery, too, to reset the adaptive strategy.

I run 1/3 of a can of Seafoam in the gas tank every few months and use good gasoline just to keep things clean. Hopefully your issue is just something simple. Good luck.

 

[jscobra04]

check for vacum leaks and clean the mass airflow sensor

 

[03cobra#694]

check for vacum leaks and clean the mass airflow sensor

I`d start here,and take a look at the air cleaner to see how dirty it is also.Let us know what you find.

 

[SnakeBit]

Since the exhaust is a horrible environment to live in, and since your O2 sensors have been living in this environment for at least 5 years, why not change them out first. Even the best electronics can have a problem living in such an extreme environment, and we all know that Ford rarely used the best. After 79K miles and 5 to 6 years, I'd say that would be your best bet. But that's just me.
op:

 

[hotcobra03]

codes

guess po171/174?

my stock 03 has had those codes also...mine is #1815,i see yours is close..

i found 4 areas that had vacuum leaks,

1st was the pcv valve and hose,,1st run cobra has a different setup and valve,,

on the back of supercharger (2 black rubber elbows)you might see the black elbow rubbing together

the the vacuum harness itself,,i removed it and blew/sucks on each line,,found 3 bad lines...

my cobra has 244k and runs like new,,

 

[Evilspyderman]

Thanks for all the info guys. I have been wicked busy with work so I haven't got a chance to do much. I am going to grab some seafoam today and some sealant for my intake. A few months ago I cracked the elbow on the stock intake where the pcv tube connects from the valve cover. I thought I had sealed it up but the stock plastic is old and has endured some heat so it breaks kind of easy. I'll pull it when I change the filter or I might splurge and buy a JLT CAI. I am affraid once I start modding this car I wont stop. Thanks again.

 

[97desertCobra]

I had the same codes with my 97 a couple years ago when it was mostly stock. Check for vacuum leaks and the 02's and dirty MAF. My issue ended up being the MAF. It got dirty and started throwing codes after I cleaned and re-oiled my K&N filter. Should have let it dry out more.

 

[04Sonic]

Check the O2'S

 

[KILRSVT]

cleaning the mass air and replacing the 02 sensors wouldnt hurt.however i think a vacum leak is whats going on here the car has 79k and the heat cycles are starting to affect all the rubber and plastic components. a good way to find your vacum leak is with a can of carburator cleaner or brake clean and spray it around all the intake system and vacum hoses.when the idle starts to stumble or it raises you have found your vacum leak .good luck.