Code 34 causes???

The Darkside

Heavy Metal Thunder
I need some help w/ this..... I took a drive in the car last night & went by the local Home Depot. When I came back out & tried to start the car(was only gone 10 minutes or so) it was real hard to start & when it did it ran really rough.. The scan master was acting strange too & showed no data... I unplugged the scan master & plugged it back in & it started working, but I noticed my o2 cross counts were not moving & neither were my integrator #'s. I shut the car down & reset the ECM & car started right up & ran fine back to the house.
Tonight when I got home I started it up & it threw a code 34 immmediately. Car was still idling fine & I let it get up to normal operating temps, but noticed the 02 cross counts were not moving at all. Shut the car own & reset the ECM again & restarted the car. This time car idled fine, the o2 cross counts were cycling quickly & Integrator adjusting normally. My blm's were around 125.
Shut the car down & restarted threw a code 34 again, cross counts not moving, plus I noticed that my IAC #'s were at 0. Usually I see somewhere in the 30+ range, so not sure if that helps to point out my problem??
Any help would be greatly appreciated!!!

The Darkside

Trouble Code 34 indicates that the Mass Air Flow (MAF) sensor is reporting less air is entering the engine than makes sense based on RPM and TPS. The MAF sensor produces a frequency output; around 30 Hz at idle to 150 Hz under acceleration. The frequency varies proportionally to airflow. The ECM monitors the frequency and thus determines airflow into the engine. Typical idle MAF is 5 to 7 grams per second.

The conditions for setting this code are:

no Code 21 or 22 (TPS Error) present, and
the air flow reported is < 4 grams per second, and
TPS indicates 10% or more throttle position, and
the engine speed is 1800 RPM or higher, and
the above conditions exist for over 5 seconds.

Typical causes for this code include:

1) Faulty air ducting to or from MAF sensor
2) Faulty ECM-to-MAF connections
3) Poor routing of MAF harness (i.e. near coil packs)
4) Maladjusted TPS sensor
5) Defective MAF sensor
6) Defective ECM

Well, that out of the way..... sure can confuse even me at times with too much info..

Pull uppipe off throttle body, remove plug from maf and see if it idles fine, if so bad maf....BUTTTTTTTTT///
I know this for a fact..
If the car was running fine before, and now is running like crap and threw a code, then i say the code is a bad code..... its a BS code from low voltage or no ground.

The reason i say this is its all about voltage, vd, and no ground, and i am not a engineer by any standards, so i cant go into detail and explain... but from reading your post i think i know the answer..

First, i think you should turn the key on and see if the volt light comes on the dash, if not, ODD issues with low voltage since the alt would not be charging.
Replace bulb.
See if change in car after you charge batt with trickle charger.

You saying the scan master had no data tells me there is no ground, was it totally blank or ---? What chip are you using?
--- is no ground.... there is your problem, if thats what you saw...

Hate to see you spend money when the car was on the fritz when it was something simple.

Can you post back and let us know?
Thanks for the reply..when the car was acting up, the scan master wasn't completly blank, it lit up(just lines), but no data.
I do believe that my battery may be going bad...The reason I say this is because it's been dead enough to where I've had to jump it a few times in the recent weeks after sitting for a few days. When the car is started the battery shows 13.5-14.1 volts, so I'd guess it's not the alternator??
The volt light DOES light up with key on.
Chip is the extender

Can a bad o2 possibly cause these problems?

When you say to pull the up pipe off, do you mean when the car is running ok or when it acts up again & throws a code???

The Darkside
Ok, I got a chance to look at the car again today & it started right up & I brought car up to normal operating temp..seemed like everything was ok so killed it & then restarted. This time it started running very rough almost immediately, but never did throw a code. I took off the up pipe as you suggested & unplugged the maf, but it still ran change. I looked at the scan master & the AF #'s were over 140!!! I'd try to give it a little gas & it would flash to back down to around 7, but then return to over 140 when I let off the gas!! My o2's were staying right around 700 & the cross counts were not cycling at all.
Any more help/suggestions would be greatly appreciated!!

Thanks, The Darkside
ODD-- You took the uppipe off and unplugged the maf and were STILL getting maf readings????

If it was still running rough, then its not the maf, might be loose spark plug wire, ect
Does it act like its running on 5 cylinders?
this -> --- might be bad ground on the scan tool, not related to the car running like crap??? I wonder if ......
Here is a thought, check to see if all the prongs on the computer chip are seated correctly, usually it will make the ses light flicker if the chip is out or not fully seated.
Your charging system seems fine..
Bryan, I didn't check for maf readings when I had the MAF unplugged..
The car does act like it's running on 5 cylinders WHEN it's acting up. It's strange how I can start it up & it feels like it's running/idling perfectly, then kill it & restart & it idles awful & MIGHT throw a code 34

I'll definetly check the chip & make sure it's seated properly..

I'm kinda leaning towards a bad o2....anything else I could check or double check to verify this idea??

Thanks again for your input, anything else you'd like to throw at me please feel free to do so...

The Darkside
Tap it !

Mine did the same good one time bad the next. When it is running good tapped it with a large screw driver if the motor goes crazy it's your MAF. This is a commen way to test the MAF for a bad board or filament.
Did you unplug the maf, take the pipe off, THEN start the car?
Try that once it has reached operating temp and see what it does.
I havent unplugged a maf while it was running to see what it did with the uppipe off, might run like crap.
Codes say maf.

I could see the 02 being bad and the car run like crap, but do you have cc built into the chip so scanmaster 2.1 can show it on your car?

Once the car warms up, the only 2 things i can think of that it would be is 02 and coil pack and mod.
If it was maf, it would run like crap when it was cold too.

We can fix it :)
Thanks for the suggestion...I know that works on stock MAFS, but does it work on LT1 MAFS?

Bryan, I took the up pipe off & unplugged the MAF w/ the car still running, so I'll try it again the way you described.. :)

Also, the extender chip does have the cross counts in iy & it's been working great...cycling from 0 to 255 in a minute or less, so w/ that now giving me nothing but a frozen # to look at makes me beleive it might be the o2.

So far it's only acted up when the car is warmed up...
Yup, then 02 for a odd reason if now its not going from 0-255.... Did you burn it up by getting it too hot?
Ive seen them melt!
Have no idea about the LT1, i am blessed with 6 here running oem GM BW stamped maf's.

Or is it still cycling and steady 02 numbers, that would make no sense.
The cross counts seem to be cycling normally until the car gets warmed up & then....well, I'm not sure because I've shut the car off & then restarted & then noticed they weren't cycling correctly....I haven't noticed if after the car warms up & kept it running if they just start acting slower & then stopping or what..

I guess I'll go out in a minute & start the car & see if the 02 cross counts are cycling normally after it gets warmed far as I know they have been...I'll report back shortly...
Ok, I just limped the car back home... :frown:
I went out & started the car & everything was looking great, o2 cross counts were cycling, o2's wewre looking good, so I decided to take a road test...
Car was driving great & sop I decide to bump into the boost a little & see how it would react..Well it bucked & acted as if a ton of fuel had been poured into it. I pulled over & my a/f was reading 13 at idle, my integrator was locked at 100 & it was throwing a code 45.. I unplugged the MAF while it was running & saw no change in idle.

One more thing.... my boost gauge reads vacuum & boost, but the needle was stuck at 0 after the car started running badly. It didn't move at all while I was driving it home.....just stayed at 0. Not sure what to make of that????

Help me....The Darkside
You sure you didnt blow a ic hose off?
Seems your car is having multiple small issues with it.
Dont fret, gotta be something simple
I'll go & double check the things you suggested could be wrong...Man, this car is driving me I'll try & keep a smile & figure this thing out ....Thanks for your help...let you know what I find...

The Darkside
Well Bryan, we fixed 2 of the problems....

Intercooler hose to the throttle body had blown off...bad clamp, will buy a new one tomorrow..

boost gauge vacuum line blown off at a connection behind the coil pack....fixed & zip tied...

Now to figure out the maf or o2 problem that one for tomorrow...

The Darkside
cool. glad we got that settled, if we get everything squared away it will be another bad ass turbo buick :biggrin: