!danger im running lean!

[Richardcoelho]

Ok guys i really need your help once again,so please bear with me,ill start from the top, First i changed my plugs to bosch platinums and i tightened my headers and y pipe to try and get ride of any exhaust leaks,unfortunately i still do,but after the plugs were installed the car felt like it had more power but right after the initial start up as it gets warm the idle begins to get rough,the needle drops and rises slightly and not rough like really shaking but more like a vibrating rough feeling,this only happens under 1000rpm's and it also affects the oil pressure guage brining the needle below the 1/4 mark,but as you gas it above 1000rpm's the car smoothens out and the oil needle rises where it should be,so im thinking it's a vaccume leak but i checked all the hoses to the T/B and pcv valves etc and i can't find anything,i also just installed my new AEM air fuel guage and started up the car,the guage read 14.6 on the start then after a couple seconds it started to go to the lean side,and within 30sec or so it was all the way lean @ 17.9 to 18.0 but this is at idle when you give it gas around 1500rpm's it goes to 15.6 to 16.2 which is still slightly lean but when you rev it at 3000rpm's it goes slightly rich at 13.0 to 13.9 which is good.so i decided to shut it of and try again,this time after the start up it went over to lean even quicker @ 17.8 in around 5 seconds so i just shut it off for the night,i really need some help and to ask questions,like if the AEM is reading correct(which i think it is)and does it automatically calibrate to the car as my friend told me(has the same guage on a LS1) and could this be a bad o2 sensor mabe not the precat o2 cause i just changed it to a bran new bosch o2 like a week ago,please help me out guys,ask me any questions or anything,i need to figure this out,thanks.

[3.4orNothing]

Re: !danger im running lean!

i dont like bosch o2

[bigbrian442]

Re: !danger im running lean!

Bosch is the inventor of O2's, narrow and wide band.



Is your car running the stock tune? Or have you let your buddy tune it for you? If you have no vacuum or exhaust leaks, open loop AFR problems can be a bad tune.

Your wide band is placed before the converter?

[flamingchicken]

Re: !danger im running lean!

techs that i have talked to tell me that if it didnt originally come with platinum's then dont put them in, they will act funny. fyi i am not stating fact, that is the independent opinion of the lead techs at the dealership i used to work for. i run ngk iridiums in my car...

[00delbz]

Re: !danger im running lean!

just go get platinum delcos they from a dealership

[Richardcoelho]

Re: !danger im running lean!

Bosch is the inventor of O2's, narrow and wide band.



Is your car running the stock tune? Or have you let your buddy tune it for you? If you have no vacuum or exhaust leaks, open loop AFR problems can be a bad tune.

Your wide band is placed before the converter?

my PCM has been reflashed since i did the a4 to m5 swap and hasn't been touched since,and the wideband is right before the pre cat sensor.

[Blizzard242]

Re: !danger im running lean!

I'm having the same problem. I also have bosch o2 sensors.. Under wot it's fine though, but that's because our cars don't use the o2 sensors for wot.

[scream97]

Re: !danger im running lean!

Will a fuel pump out of a 1998 camaro v6 fit my 1997 v6 ???

[bigbrian442]

Re: !danger im running lean!

my PCM has been reflashed since i did the a4 to m5 swap and hasn't been touched since,and the wideband is right before the pre cat sensor.

Put the wide band in place of one of the front O2 sensors that are right in the headers and see if anything changes. Pass side would be the best for this since there is no EGR tube to leak on that side. This will force the PCM to stay in open loop and if the tune is stock it will be pig rich.

[ssms5411]

Re: !danger im running lean!

13.0 is good for N/A at WOT that is not rich ,14.7-15.00 is fine for idle and if you let off the gas it will climb up and go lean since their is no load on the motor, I would do like sugested above because you might have a exhaust leak. I ran Bosch before for 02's and for my wideband no problems.

[Blizzard242]

Re: !danger im running lean!

Yeah, I more than likely have an exhaust leak myself that I should have mentioned.

[Richardcoelho]

Re: !danger im running lean!

13.0 is good for N/A at WOT that is not rich ,14.7-15.00 is fine for idle and if you let off the gas it will climb up and go lean since their is no load on the motor, I would do like sugested above because you might have a exhaust leak. I ran Bosch before for 02's and for my wideband no problems.

you may actually have something,i do have a leak somewhere either where the headers meet the y pipe or where the headers bolt to the block,could this make the car run lean at idle,if there is too much oxygen in the exhaust it should run lean right?

[Blizzard242]

Re: !danger im running lean!

It would read lean.

[Richardcoelho]

Re: !danger im running lean!

It would read lean.

im just afraid off tightening it too much,seriously i bench over 250lbs and i kinda broke several bolt in the past lol,i think it's leaking where the headers meet the y pipe,does anyone have obx headers and do they have leaks?

[Richardcoelho]

Re: !danger im running lean!

13.0 is good for N/A at WOT that is not rich ,14.7-15.00 is fine for idle and if you let off the gas it will climb up and go lean since their is no load on the motor, I would do like sugested above because you might have a exhaust leak. I ran Bosch before for 02's and for my wideband no problems.

but if i remove the sensor from the passenger header and put the wideband o2 how will the car run right since the PCM can't read it.