Need some help... again :)

[aaaudiprotein]

Long story short... There is one shop which was about to make a "custom" chip for me, but when they Vag'ed it, we found out that my cylinder 1 and 2 had some minor misfires. I didnt feel them at all, only on cold starts- sometimes.
Ok, then they put it on a dyno blah bla blah and checked on a boost leak, my dv (forge 007) wouldnt pass 5psi?. I havent serviced it for 7 months already though. Now, car idles weird, very similar to a vacuum leak i had before, but a bit better. And misfires around 3k-4k.
So before i do anything i got a couple of questions:
could that be my DV?
coils? i think i had only one detonation right after the start, thats it.
spark plugs? I changed them in the summer with NGK iridiums.
I also tried to look/listen for any vacuum leaks but didnt find anything?
Any ideas?

[aaaudiprotein]

Also, when the car warms up, idle is getting a bit better

[aaaudiprotein]

Bump

[B5Quattro190]

i had just about the same problem with my b5 a4 2.8 Quattro w/ tiptronic. back in august, cylinder's 4 and 6 misfired due to a vacuum leak that had to be fixed, as with cracked cylinder lines to both those misfiring cylinders. my spark plugs were changed just in case if that was also the case. i spent at the audi stealershit roughly 5-600 bucks for all repairs including labor?

[aaaudiprotein]

so your cylinder lines failed?
Did u do something to your car or it just happened?
Was it misfiring bad?

[B5Quattro190]

I drove the car just like any normal being would, never hard. I discovered the problem a few months into owning the car, and the misfires were noticeable through idle and through cruising around town. As with answering your first question, My cylinder lines did fail as that was part of the reason to have my car fixed.

[aaaudiprotein]

Oh, i hope my problem is something easier :)

[aaaudiprotein]

Anyone?

[CyberPMG]

For misfires, start with the simple (and cheapest) and move your way up the ladder. First thing to do is to check and change the spark plugs. Make sure they are properly gapped (even if they come pre-gapped out of the box).

If that doesn't work, swap the ignition coils between the ones that misfire to the ones that don't. If they start misfiring for different cylinders, then the ignition coil is going bad and should be replaced. If you've never had the ignition coils replaced, it might be a good idea to replace all 4 and keep the two good ones as spares.

If the misfile continues to happen for the same cylinders, then it's not the coils (still could be replaced, but it's not needed). It could be the injectors are failing and need replacing.

I had to go through all 3 steps to fix my misfiring issue - had old APR Delco 550cc injectors that went bad. Replaced them with Bosch 386cc (TT225) injectors, reflashed the APR software, and have not had a misfire since.

[aaaudiprotein]

Thanks CyberPMG.
Update
Changed spark plugs - nothing
switched to Froge 004- nothing
Tried to unplug the MAF sensor, but it still does the same thing without it..... But now i got ESP light on!!!!!!!!!
Where else could be the vacuum leak? Cause i cant find it, and i'm 80% sure thats what it is.

[dirtybrd]

Back of the intake manifold.

[A4SoftWalker]

Where else could be the vacuum leak? Cause i cant find it, and i'm 80% sure thats what it is.

Check out the vac diagram for our cars. It also has part nos. I've it below:

1.8t vac diagram

Hope this helps u find the problem.

[aaaudiprotein]

Thanks guys, gonna see watsup tomorrow

[aaaudiprotein]

Well couldnt find anythinggggggg, now my ESP light is always on!!!
What could that be? I also cleaned my MAF yesterday.
or could that be because i gave a jump to my friends car yesterday?

[NightRoller USP]

What year is your car???
I was at the dealer one day and they told me they had to update my ecu because i would get missfires on cold starts!

Dont know if this is benneficial to you, might be something you could check into.

[aaaudiprotein]

mine is 03. But my problem is somwehere else, i'm sure about that!!!

[A4SoftWalker]

Well couldnt find anythinggggggg, now my ESP light is always on!!!
What could that be? I also cleaned my MAF yesterday.

Doesn't the ESP light stay on if the MAF is unplugged

Also maybe I missed it but I couldn't find any mention of ur coils - are u still stock???

[aaaudiprotein]

^^^ yeah, i fixed that ESP problem for now.
But still having the misfiring issues. Yeah, still stock, but i checked all the coils and it didnt help.

[aaaudiprotein]

VAGCOM results:
Random/Multiple Culinder misfire
p0300-008
Cylinder 4:Misfire Detected
p0304-008
Cylinder 2: misfire detected
p0302 -008
Fuel trim; bank 1: system to leam
p1128 -001 -Mil On
Fuel Trim Bank 1: system to lean
p1136-001
Cylinder 1 ignition circuit: open circuit
p1355 -004
Cylinder 2 ignition circuit: open circuit
p1355 -004
Cylinder 4 ignition circuit: open circuit
p1364-004
Cylinder 3 ignition circuit: open circuit
p1361-004
Mass Air Flow Sensor )g70); signal too low
p0102-002
Those in red are prolly cause i was playing with coils/maf while car was on, but what about the other ones? Vacuum leak?

[CyberPMG]

Swap the coils. Swap the coils between cylinders 1 and 2. Swap the coils between cylinders 3 and 4. Clear out the codes. When you get misfires again, do another scan. Are the cylinders that are misfiring the same, or did they change? If they changed, then the coils are going bad and need replacing.

If the misfire remains with the same cylinders, you may need to replace the fuel injectors for those 2 cylinders.

Both are easy to replace.

The open circuit codes would have been when you were playing with the MAF. It wouldn't be a vacuum leak.

[aaaudiprotein]

Update again!!!
After 1.5hrs of Vagging and thinking, testing fuel pressure and etccc, my mechanic came up to conclusion that my MAF and o2 went bad. We replaced MAF and its a bit better noe accorfing to VAGcom, tomorrow gonna try to replace the o2 sensor.

[Howard Hughes]

Who's making the custom tune?? around the burbs?

[aaaudiprotein]

I dont want to name the shop yet... But yeah, in da burbs :)))
But i live around Glenview, so i take my car to MobileOne all the time to fix something

[LampyB]

just curious, but if your MAF and 02 sensor went bad how many miles do you have on the car? this isn't uncommon at around 85K miles and up.

[Howard Hughes]

I dont want to name the shop yet... But yeah, in da burbs :)))
But i live around Glenview, so i take my car to MobileOne all the time to fix something

Why? are you the beta tester?

[aaaudiprotein]

just curious, but if your MAF and 02 sensor went bad how many miles do you have on the car? this isn't uncommon at around 85K miles and up.

Turned Adult yesterday (100K). What couldve happened is i put a cone filter before the summer, and had NO heatshield for all that time.

Why? are you the beta tester?

Something like that, if u are that interested, pm me.