Car running lean

[Onyx Z]

My car's been throwing two lean codes, one on bank one and the other on bank two. I've replaced the front 02's, had the codes deleted for the rears, cleaned the MAF, and checked for apparent vacuum leaks. The MAF is ported, but everything has been fine until now; it has been ported for about 10 months, so I don't see why it would do this now? Whenever I cleaned the MAF, it ran fine for a day, then the light came back on. The same thing happened when I changed the 02's. It still runs like normal, just the lights on and it's running lean for some reason. Are there fuel pressure regulators on LS1's, if so, I've never heard of them having one and where would it be? What else could it be? Clogged injector, bad MAF, etc? Any help is appreciated.

Thanks
Ryan

[DebianDog]

Clogged fuel filter? When is the last time you changed it?

[eboggs_jkvl]

Try the filter. If that doesn't do it, then I suggest that you get A-tap or an equivalent and get some readings. What are the LTFTs and the O2s. What is the fuel pressure? Low fuel pressure will do this. Too many things to try and guess on a board.

E:)

[smiley]

both banks are lean? i'd try to get a fuel pressure guage on there. like these guys said - fuel filter should be pretty easy to start with in case it's clogged up.

[Onyx Z]

i changed the fuel filter maybe 2,000 miles ago. i'll try that and see what happens.

i know it's hard to try and dignose a car without actually seeing, people expect me to do it all of the time at work, but maybe someone had the same problem, and could point me in the right direction.

thanks
Ryan

[Onyx Z]

one more question, what sould the fuel pressure be?

[eboggs_jkvl]

58 PSI

[Onyx Z]

it ended up being the 02 sensors even tho i just changed them. i got rid of the crappy bosch sensors and went w/ some delphi, which is basically ACDelco.

[RWTD]

Originally posted by Onyx Z
it ended up being the 02 sensors even tho i just changed them. i got rid of the crappy bosch sensors and went w/ some delphi, which is basically ACDelco.

That's wild, because I've heard that the Bosch sensors suck for the LS1's, too! Glad to hear your story, but I hate you had to go through the issues and money :(

Thanks!

[Onyx Z]

i get all the stuff for free after i buy it once (i work at o'reilly's), so i didnt got through that much money.

but today the light came back on. it stays off for about 30 miles, then it comes back on. i have no earthly idea what it could be. any ideas?

[Onyx Z]

i just pulled the codes today and they are as follows: P0171 and P0174, bank one and two fuel trims lean.

[2000 Tran Zam]

any mods? do you have an a/f gauge? if you do, you could have been running into the same problem i have been.

http://www.ls2.com/forums/showthread.php?s=&threadid=14542

also, i dont suppose you can save me some money and hook a brother up with an o2 sensor since i have to replace mine and since you get them free? :D i can give ya some money for it if youd like. Pm me, and i can also try to see if i can help you more, maybe figure out whats wrong. Thanks.

[Onyx Z]

I dont exactly get them for free. I have to buy them once, then just warranty them out through my job (O'Reilly Auto Parts).

And i figured out what the problem was. My PCV hose would kind of come apart when it got hot and cause a vacuum leak. That would explain why it was intermitent.