I'm running lean after tune HELP!
 

Hey guys well I finally got my car tuned by a profesional tuner and my 3.73 gears installed. He used HP tuners (with no wideband) and about half way home on a 2 hour drive I pop my Service Engine Soon light......So I read the codes when I get home and they are p0171 Bank 1-2 "System too lean"... It has a code for all the banks but the car runs and drives fine!! So why is it doing this and could this be a major problem? I am taking it back this weekend, because he said it is from the tune....so why would he tune it so lean that I pop a code, and how can I have him fix it?

Anyone?

I understand a second opinion, but I literally told you what was going on 3 times in this thread: http://www.ls1.com/forums/showthread.php?t=107690

Second (and third and fourth :)) opinions welcome :nod:

I learned a couple of years back it is so much easier to tune with a wideband. It makes getting the ve and maf tables correct also wide open throttle af correct. narrow band o2's are only accurate in a small band compared to a wideband o2. If your ve and maf are way out of line it will cause the computer to have to learn a lot causing a rich or lean condition.

I agree with frost and with what I also told you in the PM. If he changes your part throttle and cruise a/f back to stock it should clear up the problem. But I don't know this guy so who knows.

The problem had zero to due to the tune. Someone previously installed the wrong spark plugs in the car that were approx 1/2" too short in thread, not even close to reaching into the cylinders. I cant believe the previous mechanic didnt notice the completely wrong autolite spark plugs he was installing. You couldnt do better with a mail order tune. LT Fuel trims are within +-2%, commanded PE wot 12.8 a/f with zero knock retard on tip in, full throttle or otherwise.

It was causing random misfires and other issues. changed plugs to a ngk tr55 and car is perfect. Alot of people automatically blame the tune before they investigate other symptoms such as light idle misfires and other possible causes.

When were the plugs changed, before or after the op's post?

Hey, they guy said his car got tuned without a wideband so is it any wonder that tuning is called into question?

Do you know how many shops do mail order tunes, you think every one of them cant do a tune without a wideband? Ive street tuned HUNDREDS of lsx based cars without a wideband and dyno tuned many more than that with...

could be the breather hose in the back of the motor.
https://ls1tech.com/forums/general-m...s-3-codes.html

it was already solved with the plug change.

Amazing what something as simple as plug changes will do to a car. Mine ran like an old dog before some ngk tr55s were installed, now it runs like a pissed off ape.