what could be causing these two codes???

[Silverbird2002]

Hey all
I was just wondering what could be causing to have these two codes pop up???

p0171 system too lean (bank 1)
p0174 system too lean (bank 2)

The car is running real good and the only things that have recently been done to it was the oil pan was replaced, the spark plugs were changed out, took off the screen to the air intake for better air flow, and I ran sea foam through it and changed the oil. I also changed out the PCV valve as well. So I don't think any of these things would create me having the codes but who knows... Also would re setting my PCM do the trick? Or would it have to do more with the changing of the PCV valve?
Any input would be helpful. Thanks all :)

[Atrum Rosa]

Re: what could be causing these two codes???

lean systems tend to run well, but they also blow up. Could be many things, anything that lets in air that the sensor doesn't account for. Try checking for Vacuum leaks.

[Silverbird2002]

Re: what could be causing these two codes???

Anyone else? And thanks Atrum for your reply

[goat70]

Re: what could be causing these two codes???

he is right it is almost always a vacume leak but could also be intake leak exaust leak letting air to get to o2 sensors could be o2's weak maf sensor loose air intake after looking for all leaks its best to take in in to dealer and let them scan sensors get expensive quick if it is realy a lean mix it will damage the engine quick

[Silverbird2002]

Re: what could be causing these two codes???

hmmmm Well I did have the oil pan replaced and they said they did have to drop the exhaust down to get it out. But they put 2 new gaskets in.... weird... could it be that I need to tighten the flanges up?

[Silverbird2002]

Re: what could be causing these two codes???

I don't think it's a bad 02 sensor because I did change the down flow sensor not even a month ago. Also I changed the fuel filter out about a year ago so I don't believe it is that. I did however take the screen off the MAF but before I changed out the PCV valve the car ran fine with the screen off. I did recently have the oil pan replaced due to the fact it was rusting out. When it was replaced one of the things that the shop did was lower my exhaust to get the oil pan out. They did however put in 2 new gaskets. So I'm not sure where to start first. Should I try cleaning the MAF sensor and see what happens?

[goat70]

Re: what could be causing these two codes???

the most common trouble is a vacume leak i would start there