dc_justin

iTrader: (13)

Hey all-

I've got an 03 Silverado SS with an intercooled Radix. I've been working on tuning it with EFI Live, and notice some large discrepancies between Bank 1 and Bank 2 LTFT values... at some rpm/map combos, up to a 10% difference, with the Bank 2 always reading leaner than Bank 1. I've gone so far as to pull the radix off and re-mount it to rule out vaccum leaks, so I really hope that isn't the case...

Could this be a case of one of the O2 sensors being out of whack? Or is there something else for me to look at immediately. I'm still running a 1 bar Map sensor until mid next week when the 2 bar comes in...

Any advice appreciated.

02sierraz71_5.3

iTrader: (2)

Ive noticed the discrepancy between the banks and have just accepted it. The pcm trims fuel based on an average of filtered values from the 2 banks they are not trimmed independantly, I wish they were. I get wot readings from one bank of 850 and the other will be 930 its just one of those things with a stock computer of course the afr for that cell with read the average of 890.

If you figure out a way to solve this let me know.

This would be a good post for ls1tech or hptuners site Id be interested what jimmyblue or chris have to say.

with the widebands Ive seen they read from one point not both sides so there again you dont have complete control.

I guess variables like air turbulence, moisture and occurences in the intake could cause different amounts of air to enter or act differently on each side. I would think the total solution would be to be able to adjust fueling on each cylinder individually like many f1 engines. But we are dealing with a mass produced product and not a 50k dollar engine.

dc_justin

iTrader: (13)

Thanks for the insight. Fortunately, in my case, the values are more prominantly different in the higher vaccum ranges (25-50kpa normally), so throttle tuning shouldn't be a big issue, its just bugging me seeing that.

BTW, look forward to using your VE tuning guide this weekend on my g/f's tahoe.

02sierraz71_5.3

iTrader: (2)

Im interested in some feedback good and bad

CHarris

iTrader: (5)

My truck usually runs between 1 and 3% difference from side to side with just over 8000 miles on the O2 sensors and several mods. I'd say that my range of difference is normal.

KySilverado

iTrader: (7)

I see the same in mine 3 to 5% leaner on Bank 2. At one time I considered flow benching the injectors to see if all were flowing the same. Never did. Just got over it and accepted is as normal.

KySilverado

iTrader: (7)

I see the same in mine 3 to 5% leaner on Bank 2. At one time I considered flow benching the injectors to see if all were flowing the same. Never did. Just got over it and accepted it as normal.

zippy

about 90% of the time when i see more than a 3% varience between the left and right bank it's caused by an exhaust leak or bad 02 sensor. a vacuum leak or bad fuel pressure regulator can also cause this.

dc_justin

iTrader: (13)

Upon further review of my logs and whatnot, it appears that this huge of a variation only occurs during DFCO, and I've noticed similar things with my g/fs tahoe during DFCO, and her motor is basically all stock.

Otherwise, I'm seeing 2-3% difference between the two banks.

KySilverado

iTrader: (7)

Since my last logging looking at LTFT's I have found exhaust leaks in the DynaTech Y pipe, Passenger side past the cat during the torque verter install.