# Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected"



## 1.8T A2 (Aug 6, 2001)

I threw my car on the Ross Tech Vag-Com and these codes came up:
16684 - Random/Multiple Cylinder Misfire Detected 
35-10 --- Intermittent
and
16685 - Cylinder 1 Misfire Detected
35-10 --- Intermittent
My current mods are:
GAIC
2.5 Inch Turbo Back
K&N Cone Filter
and more but irrelevant....
What the heck is this? Can some one give me advice ?
Spark plugs? Coil pack? what would cause this? Should I not drive my car?
Ps: my careems like it's driving fine though, under normal conditions (no racing).
Anyone else had this happen?
HELP!!!!
Thanks in advance...


[Modified by 1.8T A2, 11:34 AM 12-24-2001]


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## Gatorfreak (Jan 14, 2001)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (1.8T A2)*

Relax.







I got that too the other day when I checked my error codes. Hadn't done it in about 8000 miles. Anyway, I used the search on here and found a thread dealing with that. It's very common and can occur from stalling, hitting the rev limiter, or even just starting it up on a cold morning. Use the search and you can probably find it. It's really nothing to worry about. I believe error codes that are something to worry about cause the check engine light to come on.
I cleared my error (same as yours) and it hasn't come back.


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## 1.8T A2 (Aug 6, 2001)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (Gatorfreak)*

FWIW... I do not have a check engine light....
I have an engine transplant in an older car, and besides that if I had a check engine light it would always be on since ABS is not hooked up amongst other things etc etc. Switching the engine from a 99 model to an 89 causes for quite a few cels...








Anyhow...I'll do the search and hopefully I'll find something... http://****************.com/smile/emthup.gif
PS: I hope you understand now why I wonder when I have a new code...b/c my check engine light is of no use.


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## vdub07 (Apr 15, 2001)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (1.8T A2)*

It could be nothing but in my case the plugs were mucked up and I had to replace them... no more codes after that plus the car seemed to pull a tiny but harder.


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## Gatorfreak (Jan 14, 2001)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (1.8T A2)*

Ah, I understand now. You've got a slightly different situation there with the brain transplant and all.


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## Beaker (Oct 3, 2000)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (Gatorfreak)*

i had this happen on my car in the first week i had it...i panic'd...cleared it...and it has yet to show up again.


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## rub-a-vee-dub (Sep 29, 2001)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (Beaker)*

only 1 cylinder eh? amature. i got cylinders 1-3 on my misfire







hasn't happened since though, was a cold start if i remember right.


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## 1.8T A2 (Aug 6, 2001)

*Re: Help! Vag Tool Detected Code # 16684*

My buddy who has an A2 VR6 had the same codes come up, (the misfiring kind) but his car was acting up, it was being hesitant. He figured that is was the coilpack, this happened about a week ago so I got all alarmed when I saw that mine misfired as well.
I went and reset mine, now we'll see whatup, I've been driving it hard and will be doing that tomorrow as well since my little brother in-law wants to see/feel the power...I'll have to take him for a ride.


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## Mike0105 (Dec 31, 1999)

*Re: Help! Vag Tool Detected Code # 16684 (1.8T A2)*

Yeah I get them on 2 of my cylinder's alot to. Actually I think we're part of one of VW's special edition...I call it the misfire's to much edition. Don't worry about it. 
Mike


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## MYAPRSTAGEIII (Nov 1, 2000)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (RainbowGTI)*

Yes, from what I have seen everyone here is dead on. That code pops more than the question who makes the best chip....er.....ok, close second! The OBDII scheme seems particularly touchy on some things and verifiable misfires is one of them. Can you say the Feds are concerned with unburned hydrocarbon emissions


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## improvius (Mar 6, 2001)

*Re: Help! Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (MYAPRSTAGEIII)*

When it started getting cold up here, I got a CEL from misfire codes with an UP chip. I switched back to stock and got the same codes and CEL in about a week. I took it to the dealer, who told me to drive the car harder. Since then I take the the following steps which I found on the Vortex:
1) If it's cold, hold key to start position 5 sec before turning over engine.
2) If it's cold, let car idle 10 seconds (but never more than that) before driving.
3) Drive car in high RPM at least once per week.








I have not had the CEL return, although the codes still come up once in a while. Probably b/c my car is green.


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## Beaker (Oct 3, 2000)

*Re: Help! Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (improvius)*

quote:[HR][/HR]
I have not had the CEL return, although the codes still come up once in a while. Probably b/c my car is green. 
[HR][/HR]​actually, i heard different....
Green cars are the worst for throwing codes, its due to the reflective shade on the ECU it causes it to beleive its a big green elf and it gets all confused and starts giving false codes. This is all because people dont use the search button: Search


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## AxeAngel (Mar 28, 2001)

*Re: Help! Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (Beaker)*

i had that dtc, along with 11 others, had to replace my fuel pump, wiring loom, ecu, dash cluster and some other things


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## Bug_Power (Nov 27, 2000)

*Re: Help! Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (AxeAngel)*

I would get random 1-3 misfires for a while, then my #1 coilpack went bad. An easy way to check for coilpacks going bad is to swap 1-2 and 3-4 and see if the DTC's move to those cylinders. I ended up haveing #1 go completely out on me.


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## El Romano Loco (Sep 8, 2000)

*Re: Help! Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (Bug_Power)*

I have gotten those codes plenty times before, after replacing the plugs hasn't happened again. I put in NGK Laser Platinum's, perfect plugs. 
Adrian


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## 604Racing604 (Jan 12, 2002)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (1.8T A2)*

I got misfires too.
I looked in the K&N cone filter I have after one of the episodes and it ended up being water in there. I think my misfires are due to water. But not completely sure.
Does anyone know if the car goes into limp mode if a misfire has been detected?
Gary


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## mrkrad (Nov 9, 2000)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (604Racing604)*

I got that exact error on "startup". My car had 2600 miles. It was VERY cold those days in atlanta, and it only threw the CEL on the startup.
I figured crap gas + cold caused it. Hasn't come back yet.


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## rub-a-vee-dub (Sep 29, 2001)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (wolfsburg_de)*

amatures, i get misfires in cylinders 1-3


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## M0 (Nov 29, 2001)

Hman and I did some runs a couple weeks back with the VAG in my car looking to calculate block 120 and in the backround he checked for misfires. well after running the test in third gear and mashing it then letting off the gas on the way down I got misfires in cyl. 1-2 I took it into my VW dealer the next morning and asked the to scan the system. Afterwards I was informed that unless the misfires moved around to different cyl. 's then we might have a problem . Later I was also comforted by the fact that in the Bently manual it states that misfires totalling 5 or less are normal and not to be considered a malfunction.


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## greedspeed1 (Apr 28, 1999)

*Re: Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (1.8T A2)*

2001 car had a bad production run of BREMI coil packs starting in about November ended about March, the MIs fires typical happen under deceleration about 2-3000 RPM


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## torabear (Jan 28, 2002)

*CEL Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (wolfsburg_de)*

Hi Andrew,
My '02 1.8t Tip has only 1600 miles, but the Check Engine Light have been on twice. 
Two weeks ago, the service guy put injector cleaner and erase the memory when he found misfire on cylinder 4.
Today, they said the fuel injectors have to be replaced. But it's a back order part.
How could the fuel injectors go bad so quickly? Please advise any comments. Thanks.


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## VWTornado (Jan 16, 2001)

*Re: Help! Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (improvius)*

quote:[HR][/HR]I have not had the CEL return, although the codes still come up once in a while. Probably b/c my car is green.[HR][/HR]​hmm, must be a "Green Thing" cause I got cylinder misfires in 3 of mine.


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## torabear (Jan 28, 2002)

*Re: CEL Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (torabear)*

This is a update to my previous post.
Following is the message that service advisor replyed to me: 
RANDOM.MULTIPLE MISFIRES DETECTED , 16684 P0300 008 
CYLINDER # 4 16688 P0304 088 
YES, THE FIRST CODE IS THE SAME AS DETECTED ON THE LAST VISIT BUT ONE CODE CAN MEAN SEVERAL THINGS. THE CODE MAY HAVE STOOD FOR A SPARK PLUG FAILURE, SPARK PLUG WIRE FAILURE, ANY FUEL INJECTOR, POOR GAS OR A TRANSMISSION CONCERN. 
THE FUEL INJECTORS ARE TO BE CLEANED BEFORE REPLACEMENT IS AUTHORIZED BY VW. WE CLEANED THE INJECTORS, WHICH USUALLY FIXES THE PROBLEM. BUT WE ARE INSTRUCTED TO FOLLOW THE DIAGNOSTIC FLOW CHART, CLEAN THE INJECTORS, IF PROBLEM PERSISTS, REPLACE THE INJECTORS.

Please advise any comments. Thanks.


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## sile031 (Feb 1, 2010)

*Re: CEL Help! Vag Tool Detected Code # 16684 "Random/Multiple Cylinder Misfire Detected" (torabear)*

So engine is 1.4TSI 170bhp and no engine modification, I have no symptoms while driving, I do not feel the drop in power. I have 30 000km.
But I get the error:

_Quote »_000768 - Random/Multiple Cylinder Misfire Detected 
P0300 - 001 - Upper Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 0
Fault Frequency: 3
Mileage: 30087 km
Time Indication: 0
Time: 07:16:03
Freeze Frame:
RPM: 1167 /min
Load: 31.8 %
Speed: 0.0 km/h
Temperature: -1.0°C
Temperature: -4.0°C
Absolute Pres.: 1020.0 mbar
Voltage: 14.605 V
000769 - Cylinder 1: Misfire Detected 
P0301 - 001 - Upper Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 0
Fault Frequency: 3
Mileage: 30087 km
Time Indication: 0
Time: 07:16:03
Freeze Frame:
RPM: 1167 /min
Load: 31.8 %
Speed: 0.0 km/h
Temperature: -1.0°C
Temperature: -4.0°C
Absolute Pres.: 1020.0 mbar
Voltage: 14.605 V


what I have done, I change the coil from first cylinder to the fourth cylinder. And now geting error on *Cylinder 4: Misfire Detected*.
Any help would be appreciated. Did I need to change all 3 coil pack or only the bad one? Or it is something alse?


_Modified by sile031 at 2:55 AM 2-2-2010_


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