Misfires

[WillLine]

2001 LS V8 Sport Package

115,000 miles

I am experiencing misfires. Especially under load (going up hills especially) it fills like the transmission is slipping. The check engine light was on but now it is off.

I took it by AutoZone and got the following codes and descriptions:

P0171
The PCM has determined that during testing, the fuel system for bank 1 was too lean. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank)

P1131
Lack of H02S switch - sensor indicates lean

Thanks,

Will

 

[jumpman6235]

please search... replace ur coils/valve cover gaskets (if necessary) and spark plugs

 

[WillLine]

Thanks for the reply, do you recommend replacing all the coils on bank 1 (passenger side if I am not mistaken)?

 

[JES_LS]

Replace your o2 sensors. One of them is not switching and is reading lean.
The computer has already exceeded the % of fuel trim that is is allowed for adapting to conditions and now is blowing the whistle.

Replacing the O2 sensors will clear resolve the issues with the codes.
Although you may still have issues with the coils.

I have misfires in my ls and it still has not thrown a code.

 

[WillLine]

Thanks!