Alright...I just bought this camaro and for the most part most of he sensors, hoses, wires look either new or in really great shape. Previous owner said a v6 crate motor was dropped in less then 2 years ago. So Here's the problem, When I start the car it doesnt want to stay on unless I give it some gas and get it warmed up. Whether the car is cold or warmed up the idle is fine as long as I dont turn on the A/C. When the car is moving it runs great. But when I stop at a stoplight with A/C on it will almost stall, but it doesnt occur everytime. Now the idle still drops without the A/C on but R[ms dont drop low enough to cause a stall. So I bought a ECM reader and it spit out 12(Diagnostic Mode; no distributor signal to ECM;system pass, 34(MAF signal voltage or freq is low during engine cruise;MAP sensor signal voltage low during ignition on), and 44(Lean exhaust indicated left side on dual oxygen models). I've read other post regarding 34 and 44 and I hear O2 sensors, Vac sensor, Maf sensor, Iac, EGR, Distributor control module, ECM, etc etc etc. I know everyone circumstance is different but it seems that the answer to the problem is a shot in the dark. Just keep changing parts till you fix it? Im not an automotive mechanic but I do have some mechanical and electrical aptitude. So I'm just curious where do I start to figure out the problem? Problem is alot of these sensors LOOk new and its hard to attribute a problem to a sensor that looks new. So please give me some advice. Thanks.

 

Welcome Aboard!

I can guess there might be two or more problems.

First, the IAC should attempt to keep the idle RPM at target no matter what else is happening. Make sure the IAC is clean and active. Make sure the TPS is reporting correctly.

The other possible problem is an intake leak somewhere after the MAF. An EGR, PCV, intake gaskets, intake duct, injector O rings, hoses, brake booster, and any other potential vacuum leak is a suspect. This will cause both the low MAF reading and a lean condition as you report.

 

Well now that got to thinking, the service engine light didnt come on until the car almost stalled causing me to think that when the car almost died it threw the 34 for the maf sensor low voltage. So I'm beginning to lean towards the IAC as well. I'll check it out today.

 

OK quick update. I havent replaced or adjusted IAC valve because I work 10-12 hours a day and really dont have time till the weekend. However,
Today the car kicked a new code 32.
32 -Barometric Pressure (BARO)sensor circuit failure
-Exhaust gas recirculation (EGR) valve diagnostic switch
closed during engine start or open when EGR flow requested
by ECM
-Electronic vacuum regulator valve (EVRV)error(EVRV controls
EGR vacuum

With that said any new theories? or stick with switching the IAC?

 

im having a very similar problem i was getting both 34 and 44 the parts ive changed are

oil pressure sending unit
plugs
wires
distributer cap
rotor
knock sensor
most of the vac lines
alternator (of course the batts dead)
and the feul filter

now it got the 34 code gone but it just came out with a code 44 now im kinda at a loss because in the haynes manual it says it could be alot of different problems im getting the new battery sometime next week and im probley going to try and change the o2 sensor and see if that could be the problem, see its running fine good smooth idle (no idea what rpms are tach is broke) but i hate having a light on and it uses a mega f-ton of gas especially for a v6

 

Man... Well like I said I kicked out the egr code once, and its one of the parts that looks like it hasn't been changed
So I'm starting on that end instead. So I'm going to replace egr and pcv and see what happens.

 

yeah sorry i forgot that i changed the pcv valve that did help a little bit but really didnt make much of a difference at all but those are always a good thing to change but i think i will have to check my egr how do i tell if its bad? sorry im not a mechanic by any means i am a back yard tinkerer lol