Need Help, System Lean Banks 1 and 2

[13 ZL1]

I am getting P0171 and P0174 intermittently. I usually only get one at a time and it can be either. It seems that it only occurs when it is warm out. I checked all of the connections and can't find anything loose.

Here is the history.
Mods
DT Shorties
CAI Intake with ADM Scoop
Clear Image Cats
Stock Catback
Factory Tune

No codes up to this point.

Added
VMAX Ported Throttle Body

Got the first P0174 here.

Got dynoed at this time.



Added VMAX Ported Intake
I got codes more frequently after adding the intake.

Added
Corsa catback

When the muffler guy installed my exhaust, he said my Bank 2 cat was shot from running lean. I have not fixed that yet

I then got tuned. I was expecting the tune to get rid of my lean problems but it did not. Here are my results after tuning.


At this point I am puzzled. I am thinking of getting HP Tuners or something so that I can log data to try and figure out what is wrong. Anyone have any ideas?

[Stingraye]

Well your a/f ratio definitely got better after the tune. What kind of tune did you do and how many miles was it driven before the light came on again and was dynoed again? If it was relatively soon it may be a premature fault if the adaptations were still hovering around max lean. Two main factors to keep in mind with a lean fault set are 1: unmetered air leaks, as in any air entering the engine after the MAF such as intake gaskets or an improperly secured intake port. 2: The other which many people overlook is exhaust leaks. Most people think an exhaust leak will just blow out exhaust gases ,when it can also draw in outside air and cause a false 02 reading. Just keep in mind that a lean fault is set by monitoring the 02 sensors and that 02 sensors dont actually know how much fuel is in the exhaust, only oxygen. With a ported intake and tb, more air in = more air out. If this isn't properly compensated by a good tune, then you're not really getting the proper a/f ratio. If all of your intake and exhaust is properly sealed (only way to be 100% sure is to smoke test it) then a good custom tune for your exact setup may be all that is required. Good luck, hope this adds some insight.

[13 ZL1]

I am not sure what you mean by what kind of tune. The light first came on about 500 miles after getting tuned. I got another yesterday about 200 miles later. I think I have an exhaust leak after the cats. I have found small puddles of sooty water on the garage floor. I don't see how an exhaust leak after the O2 sensors can cause this problem. The problem only seems to occur in warmer outside air temperatures.

[Stingraye]

I mean is it a generic tuner like a diablo sport or did you get a custom dyno tune professionally done for your exact setup? And an exhaust leak after the cats won't affect a\f only before.

[13 ZL1]

It was custom tuned by someone who is supposed to be good.

[Stingraye]

Well your best bet would be to get in contact with him and let him know you're having some a/f issues with a ses light. Or you may need to get your intake system smoke tested to make sure there's no air leaks, but hopefully your tuner can take care of it.

[13 ZL1]

I was getting the code before the tune. I was expecting the tune to fix the problem.

[camaro1]

you need to get a scan tool and see what your fuel trims are at.

[Slowhawk]

Are these people taking your car out and driving it while scanning?(correct way) Or just throwing it on a dyno,doing WOT runs and calling it good?

I wouls figure street driving it,while scanning would bring out the problem.

[13 ZL1]

I took my intake apart. There was evidence of rubbing on the coupler between the intake tube and the throttle body. There was also dirt on the MAF sensor gasket. I guess these both could have been leaking. I put everything back together and tightened the throttle body and intake bolts.

[JLE58]

Sounds like the tune is off to me. Most of these cars with a good CAI will get a lean code on both banks. should be an easy fix for any decent tuner. They need to drive the car do some date logging and adjust the fuel correctly. lean codes, cat codes, and o2 codes are all different. I would bet money that your car is truly running lean because of the fuel trims are off.

[JLE58]

Ive got a few hand held tuners laying around if you want one let me know me. For the mods you have and if thats all your going to use for a while a diablo or sct should be fine. I use hp tuners pro but thats a larger investment and not as user friendly and not really needed untill you start with cam and/or FI.

[13 ZL1]

Originally Posted by JLE58

Ive got a few hand held tuners laying around if you want one let me know me.

PM me the details and I'll consider buying one from you. I have a scan tool that is capable of logging and downloading the data to PC. I have not used it yet so I don't know how well it works.

The frequency of codes decreased after the tune. I went about 500 miles before the codes reappeared.

Why is dyno tuning insufficient for adjusting the fuel trims?

I made a couple of WOT runs yesterday and did not get any codes. I didn't push it too much since it was raining.

[camaro1]

get a scan tool and look at your fuel trims,, you will find your tune is off,, unless it was tuned on a load dyno and the tuner was doing a full tune you would not know this till you drive the car,, driving on the street and a wot dyno run are not the same. you have a portion of your maf tune that is wrong and causing your fuel trims to go into the double digits and setting the codes,, if all your exhaust connections and maf/intake connections are good