I have a 06 SS and the computer thinks it is running lean fuel trim on tech 2 show 32% on long and short term. fuel pressure is about 57psi. Plugs are black(???). idle reves up to about 2300 and then back down until it tries to die and then back up again.

Replace MAF sensor (becuawse I had a P0101 and it hasnt come back)

BAck pressure test is ok

O2 is toggleing between 50mv-950mv(unplugged is is 450mv and runs the same)

cleaned TB 2x

flushed injector2x

PCM is as upto date as it gets

I cant find a vacuum leak for the life of me but the guage will go down to 10hg with RPM and then up to 25hg when it idles up

I cant think of any other test or pieces replaced at this time so ANY help would be greatly appreciated

 

There is a TSB out for the injectors. I wonder if you may have a bad injector ? Causing it to run lean. Just my 2 cents ??

 

My car is ideling like that and im throwing a p0101 too. I replaced the plugs and they looked fine. Now im going to get a new MAF, i think ithe AEM got wet one to many times. I tried to clean the MAF with electronic parts cleaner, aand it still isnt working.



Can someone confirm that my MAF is bad before I drop 153$ on a new one?

Oh, and my car runs just fine if its at 133 degrees or aboue, anything below trhat and it wont even idle. you have to bounce the revs between 2-3k

 

silly question.....but you did check your air intake/filter....make sure there's nothing blocking the air flow right?

 

If your asking me, i put on a new filter as well.



Any help is much appriciated

bump

 

You said your spark plugs are black so try swapping them out and put in the stock ones.

 

I'll venture a guess as to too much air and not enough fuel:

"42.5 injectors, 2.79 pulley"

Mine started running lean (after 6K rpms though) on 42# and a 2.8 pulley. My plugs were black as the ace of spades too.

60# and a tune fixed it right up all across the board.

 

Im guessing that my AFR is good because my plugs are nice and choclately brown. I have no wideband.

bumpy

 

After replaceing MAF I no longer have a code p0101

Only code is a p0171 (feul system bank on lean)

I have check the injector with the tech2 and a fuel pressure guage all test the same. Removed fuel rail and tested injectors of leak down (visible signs of fuel at the tip of the injector with key off)

Air intake has been check double checked and then rechecked I dont believe i have a lean condition i do not think i am burning unmetered air.

I cleaned the both MAPs and small changes but not enuff to matter.

I have read every bulliten on a P0171, p0101, and p0300( i beleive this code is being cause becuse the car get so low on rpm it starts to run rough)

the plugs are not black they are factory the electordes are black indicating a false O2 reading(rich not lean) on mine the car IS loading up on fuel and then revs up to keep it from dieing.

Just wondering if someone has had this and replace TB, MAP(one or the other or both), PCM, O2 whatever

OR if anyone would know of a test I could run on the car, sensors my brain anything would be helpful

And thank to you guys who have already replied I hope my awnsers make sence

 

well, since you have access to a tech2....do you also have access to tis2web???? Make sure you have the current calibration on your PCM. There have been some updates to address the p0171 code.

 

Yes I have reprogramed it once and tried reprograming remotly with pass threw and with the new tool (cant think of the name at the moment)


It is as up to date as i can get it(I think)

 

sorry man you got me, does sound like a bad injector though, or a decent sized vacuum leak.

 

Im no car god. But it really sounds like a bad injector as i mentioned earlier on. I could be wrong. But, if you did replace all 4 of them and your problem went away. I wouldn't be surprised ! Just my thoughts !!

 

this still doesnt explain my problem. after the car is warmed up it runs just fine.

 

I would say if it runs bad when cold and not when warm check 1/1 O2 sensor

basically I think you need to look at what affects the car in open loop and what chenges happen on closed loop.

 

I wonder about the coolant temp sensor. I had an old 94 Z24 that did something similair. I wonder if its worth giving that a try ?

 

This was mo thought too, but my code if for MAF

 

bump

 

I had this exact same problem when I bought my cobalt this past august. I was throwing lean codes out the ass. I bought a K&N Cold air intake and have not thrown one code since. These car should not be running lean stock, they are tuned from factory to run rich because of warranty issues. If you got your stock cars richness tuned out, you would gain probably about 15 - 20 horsepower. I got my car dynoed and it read my car at 10 afr. Thats rich as hell and the stock tune with a K&N CAI. Get a CAI and you won;t throw anymore codes.

P.S. I see you live south of da burg...I'm guessing you mean pittsburgh. I used to live south of the burg as well, in waynesburg, pa. Ever hear of it?

 

I have an intake, already. Too bad i think i totaled my cobalt last night.



Yes i have heard of waynesburg. I live in Masontown, and i work in Carmichals. Shitty little area, huh? lol

 

yes it is. I have family that I rarely speak to in carmicheals lol.

 

I work at a pretty big machine shop down behind soloman dodge.

 

Well Here is the update

problem 2 small unhearable and unseable exhaust leaks and the biggest one is what fixed the majority of the problems 1 ant the manifold to pipe fixed this and car ran better but still had lean code and surged the onther leak was all the way at the cat pipe to muffler pipe fixed this and lean code went completely way and car ran great. keep in mind this leak wat 2.5ft away from 1/1 O2 sensor maybe farther.


Just though I would let you know