New o2 sensors and still getting lean code.

[Cobra351]

well I went and bought 2 new 02 sensors because i was gettin lean code.Put the new ones in still getting code.Disconnected the battery for about 45minutes.I get this with the key on engine off or key on engine running.I have set the fuel pressure from 40 to 55 psi and it does nothing.I also have a A/F meter and it stays in the 3rd red bar and will move up to 1 yellow bar. I have good vacuum.I dont know what to do next.It was running fine before I did my head swap.even the A/F guage would bounce around like it should.I put on the new edelbrock heads and now I am getting this lean condition. I honestly believe it is a ground,because when I turn my key on the Bar light on my A/F guage is already on the 3rd bar,not at the bottom like it should be. But i dont know where to look for the ground. I have checked around the injector harness but dont see anything.I need help.

 

[Cobra351]

Noone has had this problem

 

[95YellowGTbeasT]

does it blow smoke out WOT?

 

[slvrbullit302]

the engine ground is located at the drivers side on the frame rail in front of the tire and runs to the motor mount bolt, i also think there is one on the passenger side. Did you re-install all the smog equip or remove it all i.e. the stainless tubes that connect to the back of each head, Could be a leak there.

You may also want to check the connectors at the o2's real good and make sure they are not burned or damaged in any way. One of my locks was broke and it vibrated loose just enough to throw a lean code on that bank.

One more thing to check is the connector that runs between the P/S pump and the block. That is where the o2's merge into the main harness.

 

[Cobra351]

Thanks for the reply.No it isnt smoking at WOT. I am pretty sure it is not getting a return signal or ground. I looked in a mitchell on demand book today and am trying to figure out where the ground is for the o2's. sensors are new and when i replaced them I was gettig exact same reading on my gauge and also throwing same code.(Oxygen sensor not switching).

 

[mytight95]

i am still getting this code on mine after replacing my o2's. An 95gtyellowbeast, mine does blow smoke at wot, black smoke, to answer your question



sorry for the thread hijacking COBRA351

maybe someone can help both of us

 

[slvrbullit302]

Cobra351: that connector I am refering to is to the right of the crank pulley attached to the timing cover, it is very easyily overlooked on re-install, that is the very first place I would look if it was me and I my memory serves me correctly the chassis ground for the O2 circuitry is the point in front of the battery on the radiator core support.

 

[Cobra351]

Thanks for all the replies.I will get out today and check out all that was mentioned. Will post later on my findings. BTW- Happy Easter!

 

[Cobra351]

Well I am beginning to think that I am not getting a good seal where the smog hooks up.I went out and unbolted the smog on the back of the heads and put some gasket sealer around the holes.How can you tell if the holes in the smog are lined up exactly with the holes in the head?