clg82

iTrader: (2)

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?

clg82

iTrader: (2)

Anyone?

Frost

iTrader: (45)

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

MCBRIZ28

iTrader: (2)

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.

JDMC5

iTrader: (3)

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.

CalSpeedPerformance

iTrader: (64)

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.

98Camarod

iTrader: (43)

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

Frost

iTrader: (45)

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

CalSpeedPerformance

iTrader: (64)

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...

Black98T/A

iTrader: (5)

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

CalSpeedPerformance

iTrader: (64)

it was already solved with the plug change.

Blackhawk777

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.