Bill Reid

iTrader: (14)

If someone could edumacate my slow mind...

Obviously there are lots of front mount truck kits out there (that combine driver exhaust with passenger exhaust in a certain manner) and running great for their happy customers... my question is... with apparantly no primary oxygen sensor monitoring the passenger bank of cylinders prior to the turbo how can the PCM know if that bank is running lean or rich? Obviously tuners get around that... but how?

Bill

TrickTurbo

iTrader: (12)

Bill some put the o2 in the up pipe or in the down pipe. either way your tuning tools are as a whole, not bank to bank. The computer is compareing the two sides but as far as I have seen you can not tune side to side with the GM computer. AFter market sure its possible.

Bill Reid

iTrader: (14)

Ah... OK... I have alot to learn when it comes to tuning. I generally did alot of idle and part throttle monitoring (via TechII or EFI Live) for my tuner several years ago... fuel trims and such and they were seperated by bank... makes since that I never saw seperate tables for each bank on the factory PCM. Hell, even the FAST Bank-to-Bank computer I had on my C4 only used one wideband. Makes perfect since now. Thanks for the clarification

Bill

MrXerox

Interesting point, but if the PCM is not getting an acurate read of that passengers side bank as a whole and it combines that reading to the drivers side bank that is to form its conclusion, would the calculations still not be wrong to some degree?

TrickTurbo

iTrader: (12)

Yes and no. Yes there is some degree the tuning is will be off for that perfect tune. and no becuase it has little effect on the over all package.
On a stock truck there is even a split from bank to bank. The only way to have a perfect tune for ever cylinder would be to have a fuel mgnt. system that is true seqeuntial, with 8 02 sensors. Then you could make an adjustment per cylinder. But is really not cost effective, being that good o2's are not cheap.

BigTex

iTrader: (16)

I have always watched both banks for various reasons. Its a little easier to diagnose if you have an intake or exhaust leak and which side the problem is on, or track down an injector problem. I would think that having one O2 reading after all 8 cylinders would mask problems more.... A semi-clogged injector would only account for 1/8th of the O2 reading instead of 1/4, making the issue less noticeable to the vehicle and user.

How many times have you guys had the readings from the two banks of O2 readings spread way apart? I've had my trucks do this several times and its always been a clue that something isn't right. Usually its an exhaust leak or something, but its important because it affects fueling.

Lord Aries

iTrader: (6)

On this Livernois setup the passanger side O2 is mounted in the collector of the passenger side header and is seperated from the driver side inlet by a baffle... See attached picture...

MrXerox

Hard to argue with the old livernois design in any way

thunderwagen

iTrader: (3)

Try to change the spark plugs then you will want to argue with it.

Bill Reid

iTrader: (14)

Ah... very nice... do you know if the new Livernois log manifold does the same?

Bill