ajrothm

Just got my engine back in, started it up on the previous tune, engine combo is exactly the same.. Tune is 3 bar SD using HPT.

I have some weird **** going on though.

In closed loop the Bank 2 O2 drops out to 50-250mv (lean) like the sensor is dead, Ofcourse it starts running like ****. The Bank 1 O2 switches (cycles hi/lo like normal trying to hit 450mv)

If I force it in open loop, both O2s track exactly the same and read 500mv (ish), the wideband matches that at 14.5 ish.

So the question is, how can O2s read properly, track and match in OL, yet when in CL one O2 shows lean....(Ofcourse then the STs jump)

I want to start working on the tune but I really need the O2s matching. They are NGK sensors and have about 400 miles on them.

Thanks in advance....

joecar

Swap NBO2 sensors across banks, see if problem follows or stays.

JakeFusion

iTrader: (7)

I would try the reversal. O2 circuit gremlins are not fun.

RonSSNova

iTrader: (3)

Alan, are you resetting the trims when you do this?
You can do it with the VCM controls.
Do you have the LTFT disabled?

I know swapping the sensors can be a bitch on C5's depending on the header brand.

Ron