Dave@Ramchargers

Hey guys, I just got the car back together today and I NEED to be somewhere in a few hours...

Quick backround

10.7-1 ported heads
236/236 602/602 110ls
6 speed
Ported TB, ported MAF
LS6 intake
30lbs injectors

Bank 2 sensor 1 does NOT cross count, it stays in the 300's range.
If I unplug the MAF both 02's cross count like they should.

Also my banks are way far apart from one another.. Ltrim 1 will be 10 or so and Ltrim 2 will be close to 0.

I cannot find any leaks in the exhaust anywhere.. I was thinking bad 02 until I unplugged the maf..

Any ideas????

jimmyblue

iTrader: (11)

Ported MAF without table changes would put you
pretty lean. But this should not be a bankwise
problem. It seems the MAF (or, running in the
MAF/SD hybrid mode) is not as good as the basic
speed density tune.

Bank-bank differences would most likely come
from intake air leaks, a lame injector, or the
thermal differences between the two banks'
front O2s. Shooting propane or carb cleaner
around the intake manifold seats would be a
good start; might want to unplug the IAC to
keep the PCM from "hiding" the effect, once
it gets to a stable idle. If you have headers
the O2 may just be "bad enough" when cool.
Might check whether it commences to cross-
counting after a nice warm-up (like rev it at
4000RPM for half a minute) and then maybe
gets all lazy again; that's a sign it's too cold
to work, at least when aged, and you might
want to try those 'vette rears as replacement.

Dave@Ramchargers

it gets better with heat.. but not much.. while driving its a little better but not much..

Also

Im getting knock at idle.. and part throttle knock thats simply amazing during low RPM, light trottle. ive seen up to 10 degrees of retard.

im just going to go pick a 02 sensor up at autozone and try it..

monodax

You also need to check to see if you have any exhaust leaks near your headers or y-pipe connections. I had major differences between the banks like you mentioned when I had a band clamp that did not seal well on the passenger side.

Dave@Ramchargers

I changed 02's and fuel trims are close to each other now.

4 versus 7..

Im still getting knock at idle and part throttle..

02 cross counts are both in the 200's 300's. The ONLY go higher if I blip the the throttle and they go richer as I let off.

I threw a code for TPS but I think its because I was messing with the IAC with Edit..

I tried adding fuel by adding to the MAF and VE table's down low but that didnt change a thing

Anyone have any ideas?? Both banks seems to be running way lean and im completely lost.

What do I try next?

jimmyblue

iTrader: (11)

One thing that kind of baffles me here is, how it can
have semi-sane LTFT values without cross-counts.
Because LTFT is the trim needed to obtain balance,
pretty much requiring cross-counts to occur and be
even.

Dave@Ramchargers

they move, just not much... within a few hundred.. 200's - 300's and thats it nothing more.

any ideas why I would see soooo much knock at idle? and everywhere else?

HumpinSS

iTrader: (1)

Check for exhaust leaks. With them pretty low like that sounds like some air mabe getting on them

Dave@Ramchargers

i cant find anything that would effect it... any leaks I have are way after the 02's..

Also my trims are now +4ish - +8ish at idle.. at cruise they are 0. What do I need to change to bring them down? Lean out the low end VE ?