NefMoto

Just looking for some less obvious reasons I would have only one bank on a stock 2.7t running a stg 1+ flash run way leaner than the other. Just started to trouble shoot this. I took some logs with setzi's tool because from 3200-4000 the car stumbles pretty hard at wot with a flashing cel. Bank 1 shows .9's on the primary 02 and bank 2 goes into the .5's? It seems bank 1 is super lean, and bank 2 is super rich. Egt sensors are coded out, and both primary o2 sensors were changed today, plugs were replaced 200 miles ago, rears are plugged in, but coded out. Bank 1 upstream 02 looked very white (lean) and bank 2 looked black (rich). Is it possible one turbo is working much more efficient than the other? Something maybe with the fuel rail? Car ran strong for quite a while, and then started hesitating only in 5/6 between 3-4k (tq peak?) I was originally thinking fuel pump, but decided to change the primaries first because I knew they were old as a first step. I have logs on another computer, and will post them up tomorrow. Thanks for any ideas!

post your block 093 readings

Are you quoting lambda or sensor voltage?

Misfires will read lean, have you done any misfire troubleshooting?

I was quoting the values from lamsbg and lamsbg2 as far as the .9 and .5 go. I assumed these were lambda, correct? One strange thing is the side that looked like it was going lean was also the side that had the blaketty-black sensor, which is the opposite of what I would expect to see, but I guess if it's getting raw fuel dumped on it from a misfiring bank that would make sense.I did some misfire troubleshooting which consisted of replacing all the plugs, and swapping the ignition modules on the airbox, and replacing the coilpacks on the offending side. I'm aware that a misfire will result in an empty-ish cylinder's worth of air being pumped into the exhaust which will make it look lean. As far as logging block 093, I should do this in 3rd gear at wot, correct? Thanks for all the replies.

lamsbg?

What variable is causing the difference in target lambda?

My guess would be dlamatr_w from a bad EGT.

What are your LTFT's?

Short and long term fuel trims are 3% or below (closer to zero). EGT's are bad, and coded out (or at least I think they are haha.). The car does not stumble on a stock file. Attached is a log from today. Originally before I replaced both upstream 02's I was only getting timing pull from one bank, with a 4/5/6 misfire code. Todays logs seems to be pulling from all 6..

Consider checking the coilpacks and the ignition amps as well..

Also, I am seeing a huge drop in boost.

You should be logging MAF so you can see if you have a boost leak.

Also, you should log pedal position so ecuxplot can filter on WOT.

Ign amps were swapped, and coilpacks were replaced. I originally thought ign amp because the problems originally seemed to be with just one bank. What was the codeword for the variable to log wot? Thanks guys. I will re-log tonight.

You need to log all of the variables that determine target lambda.

How did you code out EGT's?

Log dlamatr_w at least. There's really not that many bank specific influences on target lambda.

Use wped_w for pedal position.