Code 44 at idle...STILL will not go away! (LONG)

[d0n_3d]

I have a checklist as to what I have done to try and solve this problem. The car still continues to throw me a code 44 whenever I let it sit and idle in park or in OD/D for about 60 seconds. What happens is the car goes into open loop, idle stumbles, exhaust smells rich constantly, and walla the SES light comes on. Code 44.

It's funny because this doesn't happen ALL the time when I let the car idle...just once and a while.

Ok now for the checklist:

1. tried NUMEROUS o2 sensors...tried bosch, tried the purple wire ac delco, and right now running a brand new GNX o2 sensor

2. changed the pcv valve to a delco stock replacement, tried using an inline check valve with pcv, tried using just the check valve

3. have tried 3 different maf sensors...stock rebuilt, new tomco unit, and now using the ls1 maf sensor and translator

4. installed power plate, uninstalled powerplate, reinstalled it again

5. tried different fuel pressures, really low, really high

6. swapped out stock old worn injectors to brand new 50's

7. tried NUMEROUS chips...doesn't matter which chip i put in

8. new iac sensor

9. replaced cracked ds header with new poston's unit

10. checked for cracks on pass header and crossover pipe...found nothing

11. check vacuum pressure at the fpr...got 22 hg of vacuum which is well above normal

12. have searched everywhere for cracked vacuum lines, all lines look good and nothing is loose

13. i did remove the cruise control unit a long time ago but i plugged up the two vacuum lines going to it...

14. not related but changed to brand new te-44 turbo...all intercooler hoses are new and tight, intercooler doesn't leak to my knowledge although i could be wrong...but that wouldn't cause a code 44 i don't think

15. this happens with race gas, alky, pump gas...not gas related

16. changed fuel filter, done spring cleaning many times

17. checked to see if i had bad grounds at the o2 sensor...checked out fine...

18. egr system still works fine...car stumbles when i press the diaphragmn

19. sprayed carb cleaner all over the place in every vacuum area i could think of...car idle did not change so no leaks found

can't think of anymore right now...but you get the idea...i have tried EVERYTHING except opening up the motor or something major like that...i was told maybe i have a bad intake manifold gasket INSIDE where i can't see it...

all i know is that turbolink shows some interesting numbers when idling...

tps .42
iac counts 55-60
o2 cross counts 4-10
o2 millivolts 100-500
blm always stays at 150 unless i rev the motor
integrator tends to hop around between 128-150...mostly in the 140's...if you let it sit for a long time the integrator will be stuck at 150 until you rev


and the exhaust smells extremely rich all the time...so bad that is makes me want to pass out...no black smoke or anything just a really really rich smell...my gas mileage is OK but could be better...

does anyone have any comments on this? i am stumped totally...i have tried everything i can think of...

 

[Joe 1320]

I found that tuning the car for 128 BLMs at idle will allow the computer to at least have the widest range of adjustment. Unless your chip locks the BLMs that is. What fuel pressure are you running? Are the chips specifically burned for 50s? Are you sure the coil/module is up to spec? Some ohm great when cool but go south when they heat up.

 

[bruce]

Originally posted by d0n_3d


o2 cross counts 4-10
o2 millivolts 100-500
blm always stays at 150 unless i rev the motor
integrator tends to hop around between 128-150...mostly in the 140's...if you let it sit for a long time the integrator will be stuck at 150 until you rev

For some reason the O2 is reporting lean.
It's got to swing over about .6v for the ecm to think it's alive.

An ignition miss can cause the O2 to report lean.

 

[d0n_3d]

Originally posted by Joe 1320
I found that tuning the car for 128 BLMs at idle will allow the computer to at least have the widest range of adjustment. Unless your chip locks the BLMs that is. What fuel pressure are you running? Are the chips specifically burned for 50s? Are you sure the coil/module is up to spec? Some ohm great when cool but go south when they heat up.

yes the chip is burned for 50's...fuel pressure is currently at recommended level of 42 line off or 37-38 line on

have not checked the ignition coils i have gone WOT many times and i don't miss or anything...like i said this doesn't affect performance at all...just idle...my car is idling at around 850-900 rpms at a stop...it's programmed to idle at 775 or so

 

[d0n_3d]

i am going out right now and will record a tlink file for everyone...

 

[d0n_3d]

ok i had a thought...could the egr valve cause this problem? mine is factory and has never been replaced at 90k miles...turbolink does show the egr duty cycle working well at cruise...but shows 0% at idle (i know it's not supposed to run at idle or WOT)

but would that cause a code 44 by any chance? somebody said they changed the egr gasket and their code 44 went away...is that a possibility???

when the car idles and i press up on the diaphramn...the car does stumble...

 

[strikeeagle]

D,

You need to get the GM service manual. It has a diagnostic flow chart for every trouble code...

 

[TurboDave]

With your BLM's stuck at 150, and the INT's in the 140's (still trying to raise the BLM's even more) and even higher, you've got either a vacuum leak, or (what I suspect) a pre turbo exhaust leak. Many exhaust leaks occur at one of the crossover pipe junctions and go unnoticed. There could also be a crack in the passenger side header you might not see. But it's very likely one of those two.

Throwing parts (money) at it isn't going to help until you find out what's leaning it out so bad!!

 

[mgmshar]

Bingo, TurboDave! Your chip is only allowing your BLM to go up to 150 (no higher), and your INT's (above 128) are telling you that the car wants to be richer. The O2 sensor never goes rich (above 0.5volts), so your ECU thinks that the sensor is bad.

Based on your idle rpm (850-900rpm), vacuum readings (22") and your IAC value (55-60), I don't think you have a vacuum leak. When you have a vacuum leak, your ECU will close-up the IAC (lower number) because the engine is getting air from somewhere it's not supposed to. If anything, your IAC readings are probably too high, which could mean that your throttle plate needs to be adjusted; my recollection is that they should be around 20-30 in drive at idle, but I digress...

You need to figure out why your O2 sensor is seeing a lot of oxygen. Possibilities:

1. TurboDave is right - check for a pre-turbo exhaust leak. The leak will cause air to enter the exhaust stream and fool the O2 sensor into thinking there is excess oxygen in the exhaust.
2. Bad misfire sending unburned air and fuel into the exhaust. I would think that you could hear this if it was happening at idle.
3. Try increasing fuel pressure until you get to the point where your BLM comes below 150 at idle. Once it does, see if the Code-44 returns. If not, then your need to either re-calibrate your chip or run with the higher fuel pressure.

There are probably other possibilities as well. Good Luck!

 

[T-Type Mike]

Hi guys, I was having the same problem for the last 3 years with my car aswell. Finally I think I found my problem. I was having a no start situation when I brought the car out of storage, she would start maybe 1out of 3 tries. First thing I changed was the o2, no difference, then swapped out the original coil pack and have not seen the code 44 since. That is what it was in my case, who knows it could be for you too??? Good luck Don, Mike

 

[d0n_3d]

guys i am positive i have no exhaust leaks...i changed out my ds header to a brand new poston's unit...i was getting this code even with the stock manifolds...i have no cracks in the pass or crossover pipes...

o2 mvs are showing 150-180 at idle in closed loop and go no higher or lower...i get 0 cross counts at idle in closed loop...something is killing my o2 sensors...when i first put in the sensors it will cross count lots of times and mvs will be all over the place...but after a while the o2 sensor seems to go dead as a doornail...what is causing my o2 sensors to go bad! steve wood told me that the motor has the wrong kind of silicone sealant in it or something? not sure what that means...i do not run race gas...straight 93

i am pretty darn sure i have no vacuum leaks...i even changed the egr valve today and found out i had a really bad looking gasket...new gasket and valve and still get high blms and integrator...didn't change anything...

what i would like to know is what is causing the o2 to go bad...

my coil pack is fairly new guys...it's only 3 years old...i have new plugs and new wires...msd wires and cr42ts ac plugs gapped at .35...if i had a miss i would know it...like i said MY CAR IS NOT AFFECTED PERFORMANCE WISE...i can boost up to 22 lbs on alcohol right now and get no knock or miss or anything...smooth as hell and car flys...i am just having this at idle for some reason...

 

[Joe 1320]

The things that kill 02 sensors are silicones, leaded fuel, penetrating oils, some cleaners (carb cleaner), oil in the exhaust like from burning oil, antifreeze from a blown or partially blown headgasket.

The part I have to agree on is that the INTs and BLMs show the computer thinks the car is lean. You say the exhaust smells rich. Usually that means air is getting into the exhaust prior to the 02 sensor or faulty sensor.

 

[d0n_3d]

Originally posted by strikeeagle
D,

You need to get the GM service manual. It has a diagnostic flow chart for every trouble code...

who sells the service manual???

 

[Steve Wood]

You have been thru the flow chart at least twice. Helms did sell the manual. NOt sure if it is still in stock or not.

 

[d0n_3d]

Originally posted by Steve Wood
You have been thru the flow chart at least twice.

LOL

no kidding...my car is definitely a sh!tbox

 

[d0n_3d]

well we have narrowed it down to bad 02 sensor...even though i have put in 5 new ones in the past year it seems...SOMETHING is causing them to die in a relatively short time span...when i first put a new o2 sensor in the car it will cross count and mv at idle like crazy...blms and integrator are around 128 at this time...

after a week or two of driving the car i notice the idle cross counts get down to 0 and mvs at idle in closed loop will be between 150-180 and doesn't go any higher or lower...then the blms and integrator sky rocket to 150 pegged in a hurry and don't move at idle...

when i start cruising...i get cross counts again and mvs like normal...my gas mileage isn't really all that bad...i calculated it to be about 22 mpg on the highway...i don't get this code while cruising...blms and integrator range from 128-140 usually while cruising...they aren't pegged at 150 like at idle...

i have checked everything there is to check on this issue...something is causing the o2 sensor to read incorrectly at idle and not sure what it is...either that or something is causing the o2 sensor to die or respond poorly at idle...i was thinking about going max effort but i don't want to spend anymore money on this car and i don't want to have all that extra tuning...i have enough tuning to do right now as it is with an smc alky kit, boost, fuel pressure, etc.

 

[c&cgn]

Originally posted by d0n_3d
guys i am positive i have no exhaust leaks...i changed out my ds header to a brand new poston's unit...i was getting this code even with the stock manifolds...i have no cracks in the pass or crossover pipes...

my coil pack is fairly new guys...it's only 3 years old...i have new plugs and new wires...msd wires and cr42ts ac plugs gapped at .35...if i had a miss i would know it...like i said MY CAR IS NOT AFFECTED PERFORMANCE WISE...i can boost up to 22 lbs on alcohol right now and get no knock or miss or anything...smooth as hell and car flys...i am just having this at idle for some reason...

Try some GM top engine cleaner and then tell us whether you have an exhaust leak or not. Put the car up on jackstands when you do it so you can slide underneath it. If there is an exhasut leak there the top engine cleaner will find it. It will be totally obvious. .Trust me, we all think we have a car w/o exhaust leaks until we run this stuff!

Also, is your 3 year old coil pack a GM unit? Why not swap in a known good coil pack and module and see if it makes a difference.

 

[d0n_3d]

Originally posted by c&cgn
Try some GM top engine cleaner and then tell us whether you have an exhaust leak or not. Put the car up on jackstands when you do it so you can slide underneath it. If there is an exhasut leak there the top engine cleaner will find it. It will be totally obvious. .Trust me, we all think we have a car w/o exhaust leaks until we run this stuff!

Also, is your 3 year old coil pack a GM unit? Why not swap in a known good coil pack and module and see if it makes a difference.

i might try the engine cleaner...i guess that stuff works better than alcohol because i figured the alcohol would clean out the motor and there would be no carbon in there...

also i could try and get a new coil pack but why? like i said i don't have an ignition problem at all...i can get up to WOT 5000 rpms and there's no popping or missing...that's at 22 lbs of boost...the car idles ok...it will die sometimes when you first start it up and you have to keep hitting the gas to warm it up...

i took my car for a little drive yesterday and recorded it on tlink...o2 cross counts and mvs are all over the place like they should...blms are at around 140 and integrator between 128-145 which indicates it's still lean i guess...but at idle the o2 sensor shows 0 cross counts and 150-180 mvs at idle...