diagnosis please

[2002 v6 camaro uncharged]

Okay,
This is what I know so far map readings have not changed (so this eliminates a vacuum leak right?), O2 are workin, I only get the p0171 & p0174 with the MAF plugged in and the car drives normal with a horrible rich idle, with the MAF unplugged the car drives and idles perfect except from a cold start and only throws the codes from the MAF (no more lean codes). When I start the car with the sensor unpulgged after it has been sitting and completely cools it idles great until I start to give it some gas then it idles like crap and stalls. If I let the car warm up at idle before I try to leave then it runs fine. Is the car supposed to run perfect in speed density all the time or is this cold start problem normal.
Can someone tell me what this means?

[grayman]

do you still have the jet chip in the car?

do you still have the super charger on the car?

this 'weirdness'has been going on for a long time it seems with your car. if it were mine i would remove any possible associated mods such as the jet chip and the supercharger. i would then try and diagnose what is going on.

[2002 v6 camaro uncharged]

Everything is off the car, I had to take the supercharger off for rebuild everything is back to stock. This problem started about 3 weeks after I removed the supercharger. The last time I had this similar problem it turned out to be the by-pass valve had a ripped diaphram and was sucking on the vacuum. But the vacuum is fine this time.

[2002 v6 camaro uncharged]

Hey Grayman,
Can you do me a huge favor and when your car is completly cold can you unplug your MAF and tell me what happens. Mine will idle fine until you touch the gas then it will bog and want to stall.

[grayman]

i will try that tomorrow. on my way to work now...i don't want any surprises. DOH!

i will let you know how it goes saturday afternoon.

[2002 v6 camaro uncharged]

Thanks alot I appreciate it.

[shenanigans]

responded to post in FL section...

I jumped on the gas hard thought, didn't ease into it, and just sitting in netural.

[grayman]

Car was cold. (it had sat for day and a half)

Unplugged MAF,

Car started fine but 'low engine pwr' lite came on and stayed on.

Car idled differently than normal. sorta ruff. it would also idle up and own a bit. sorta goofy like.

when car warmed up the idle rpm's dropped (like normal)

with warm car and the maf still unplugged it idled sorta goofy but it never got anywhere close to stalling. I did not bother driving it with the low engine power light on.

turned off engine. plugged MAF back in. it runs like normal.

hope this helps.

[2002 v6 camaro uncharged]

Thanks alot I really apppreciate you doing that for me, after reading this I thought for sure it was my MAF sensor. The one I had in it was still under warning so I just exchanged it and The new one is doing the same thing.
So now I am back to square 1 and have no idea.

The reduced power mode you got is strange I have never gotten that code before with the MAF unplugged.

[grayman]

i was pretty sure you were not getting the reduced power mode as you have not mentioned it.

so with the uber charger off the car and the jet chip removed and all your vac lines restored to stock does the car throw any codes?

[2002 v6 camaro uncharged]

This is what I know so far map readings have not changed (so this eliminates a vacuum leak right?), O2 are workin, The fuel pressure has not changed I only get the p0171 & p0174 with the MAF plugged in and the car drives normal with a horrible rich idle, with the MAF unplugged the car drives and idles perfect except from a cold start and only throws the codes from the MAF (no more lean codes).

[grayman]

you might have come accross this info already. here it is just in case you havent.
+++++++++++++++++++++++++++++++++++++++++++

"A code P0171 may mean that one or more of the following has happened:

* The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters (K&N, etc.) can cause the MAF to become dirty if the filter is over-oiled
* There could be a vacuum leak downstream of the MAF sensor.

Possible Solutions

Possible solutions include:

* In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
* Inspect all vacuum and PCV hoses, replace if necessary
* Check for a dirty fuel filter and proper fuel pressure

(grayman: do you have a K and N filter? Is it over oiled? If so it could have fouled you first MAF as well as your 'test' maf units.)

++++++++++++++++++++++++++++++++++++++++++
(grayman: here is the whole section regarding p0174. It sounds like it is exactly the same but regarding the other O2 sensor)

System Too Lean (Bank 2)
What does that mean?

Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

Note: This DTC is very similar to P0171, and in fact your vehicle may show both codes at the same time.
Symptoms

You will more than likely not notice any drivability problems, although there may be symptoms such as a lack of power, detonation (spark knock), and/or a hesitation/surge on acceleration.
Causes

A code P0174 may mean that one or more of the following has happened:

* The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters (K&N, etc.) can cause the MAF to become dirty if the filter is over-oiled
* There could be a vacuum leak downstream of the MAF sensor.

Possible Solutions

Possible solutions include:

* In the vast majority of cases, simply cleaning the MAF sensor does the trick. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
* Inspect all vacuum and PCV hoses, replace if necessary
* Check for a dirty fuel filter and proper fuel pressure

+++++++++++++++++++++++++++++++++++++++++++
Here is the link to where i found the above info.

http://www.obd-codes.com/trouble_cod...gen-sensor.php

you may have to check your vac hoses again. I wonder if there is a way to check for vac leaks in the FMU diaphram? is your FMU disconnected at this time?

[2002 v6 camaro uncharged]

The Fmu is still hooked up but I already tried plugging the vacuum line and it did not make any difference.

If I completely understand everything that I you posted ^^^^^ is it saying if one of the O2 are bad it could throw both bank 1 and bank 2 lean codes?
Thanks for your help

[2002 v6 camaro uncharged]

Just bought a vac gauge and it read 19. Is this what it should read?

[grayman]

Originally posted by 2002 v6 camaro uncharged:
Just bought a vac gauge and it read 19. Is this what it should read?

i idle at about -20 on the boost /vac gauge so that is most likely a good thing for you. the vac will will move towards '0' as the throttle is increased and into the positive numbers when the blower is putting out more air than the engine is breathing on its own.

as for the codes...say if you had ONE bad injector that was letting TOO MUCH fuel into the cylinder then the 02 sensor on THAT SIDE of the engine would register the RICH MIXTURE code. You have it on both sensors which makes it sound like the maf is not calculating correctly. I am not at all an engine computer pro, though. i am just trying to help.

what is your answer regarding the possibility of an over oiled k and n filter? you have a cone filter still, right? has it gotten wet? can water mess up a MAF?