Weird misfire issue

[Cyrus221]

Hey guys,

I have a mostly stockish S4 with mainly drivability mods (trans mounts, snub, suspension etc) and I'm having a weird misfire issue. So, it started when I picked the car up about 1.25 yrs ago and a CEL. First it was b2 s2 and no misfires.. I replaced the b2 s2, cleared DTCs and drove for 100 miles. Now I had a b1 s1 and some misfires on cyl 1 2 3 WITH a system going lean. So, changed plugs and coils around 123 -> 456, the misfire didnt follow. So, now its winter and I have no heat so I just park it for 5 months, do the heaster core (almost worth paying someone 1k to do it holy fuck) and I'm back to driving it. Clear DTCs after getting new plugs, same thing (used ngk brk7es or whatever everyone always says to use). PO said he changed the packs out ~20k miles ago. So, I park it again for a few months collecting various stage 3 parts but its summer now and I really want to drive this thing, stock or not. My mechanic didnt think b1 s1 was the issue so thats why we didnt change it earlier ... changed it out this time (it was BLACK) and im still getting the misfires. They mainly occur when i'm in line getting coffee or at a stop light. Anyone ever experience this?

tl;dr system lean, misfires on 123, swapped everything around it didnt folllow, usually happens @ idle; what do?

[cinimod25461]

Did you try switching your ICM's around? If not, try that and see if the misfires follow.

[Cyrus221]

Did you try switching your ICM's around? If not, try that and see if the misfires follow.

i actually didnt switch the icms. ill do that next week when i have the garage. good call, cant believe i forgot to try switching icms lol

[vavJETTAw36]

i actually didnt switch the icms. ill do that next week when i have the garage. good call, cant believe i forgot to try switching icms lol

Get some heat sink paste ready if you pull them. Easiest way to do it is just switch the connectors not the icm itself.


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[airjawed]

Use the right spark plugs( I don't think bkr7e is stock)... use the stock plugs but gap them to 0.024 since you are going to stage 3. Also clean/tighten the ground wire on the firewall under the coolant reservoir. It sounds like a bad spark leading to codes. Heavy misfires will lead to a lean code since it only measures oxygen which will be plenty since no burning.

[frankwizzle]

Did you replace the b1s1 o2 sensor? That sounds like your issue

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[Cyrus221]

So, update: I had 30 mins today so I logged the car -- no misfires BUT I'm getting a b1 s1 error again (I did replace it earlier with a bosch one I purchased from vatozone):

Monday,13,June,2016,10:16:59
VCDS Release 15.7.4 (x64): Generic OBD2
Mode 1:Read Data

20:Bank 1 Sensor 1 Status 0.150 V 0.00 %()
03:Fuel system 1/2 status Open loop, due to system fault detected Closed loop, using O2 sensors
12:Engine RPM 802 /min
16:Mass Air Flow 4.50 g/s
Monday,13,June,2016,10:17:31:57634
VCDS -- Windows Based VAG/VAS Emulator Running on Windows 7 x64
VCDS Version: 15.7.4.1 (x64)
Data version: 20160216
www.Ross-Tech.com




Monday,13,June,2016,10:17:29
VCDS Release 15.7.4 (x64): Generic OBD2
Mode 1:Read Data

20:Bank 1 Sensor 1 Status 0.095 V 0.00 %()
03:Fuel system 1/2 status Open loop, due to system fault detected Closed loop, using O2 sensors
12:Engine RPM 790 /min
16:Mass Air Flow 4.25 g/s


I didn't get a chance to look at / clean the connectors to see if theres some dirt in there causing this. Could this be in any way/shape/form related to the heater core I did in the winter? There were A FUCKTON of wires and it was the most annoying thing I've ever done my whole life.... every once in a while I'll get an intermittent failure to the instrument cluster from a couple different things like ABS, speed sensor, etc (daz did my instrument cluster). I'd hate to be chasing an electrical ghost haha

[vavJETTAw36]

Is the instrument cluster coded properly for the ecu you have?

Do you have the actual codes the ecu is storing? It's hard to know what's going on without the actual codes. Which side oxygen sensor did you replace? Ds or ps?


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[Cyrus221]

Only the LCD was replaced not the entire cluster. However, I've never actually ... checked to see if thats what he did. He said he just replaced the cluster with an OEM screen and I left it at that. I've never pulled the cluster codes before -- how would I do that?

[vavJETTAw36]

Cyrus, when buying an ecu from someone and the ecu part is different, the instrument cluster needs to be coded to see that new part. The believe I remember recoding the abs module as well.

If you have not replaced the ecu, this is probably not your issue. But one thing to note, if you turned on the car while the instrument cluster is out, it will store the same code. The code is: "18058 - power train data bus - p1650 - 35 -10 - missing message from instrument cluster - intermittent"?

Also note this is unrelated to the oxygen sensor issue... Can you tell us which side you replaced? Ps or ds?


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[Cyrus221]

Cyrus, when buying an ecu from someone and the ecu part is different, the instrument cluster needs to be coded to see that new part. The believe I remember recoding the abs module as well.

If you have not replaced the ecu, this is probably not your issue. But one thing to note, if you turned on the car while the instrument cluster is out, it will store the same code. The code is: "18058 - power train data bus - p1650 - 35 -10 - missing message from instrument cluster - intermittent"?

Also note this is unrelated to the oxygen sensor issue... Can you tell us which side you replaced? Ps or ds?


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Oh right right. Sorry, b1 s1 is on the passenger side.

[airjawed]

Forget about the instrument cluster stuff... only the display was replaced. No need for ECU coding when this is done.

Please post your exact codes after clearing the codes and then going for a drive.

[Cyrus221]

Okay -- going to go for an hour drive today. Any recommendations on how to drive it? I plan to do mostly highway driving... when I get near my house though I have a lot of red lights to get through (4-5). Just drive normally?

[Cyrus221]

Alright -- I went for my drive.. mostly highway, with a few 3-4.5k rpm bursts in there to pass some yokels. Got home after 70 mile trip:

VCDS Version: Release 15.7.4 (x64) Running on Windows 7 x64
Data version: 20160216
www.Ross-Tech.com

Wednesday,15,June,2016,22:20:28:57634

Chassis Type: 8D - Audi A4/S4/RS4 B5 (1995 > 2001)
Scan: 01 02 03 08 15 16 17 25 35 37 45 55 56 57 67 75 76 77

-------------------------------------------------------------------------------
Address 01: Engine Labels: 078-907-551-AZA.lbl
Part No: 8D0 907 551 M
Component: 2.7l V6/5VT G 0001
Coding: 06711
Shop #: WSC 87119
VCID: 3467776E04DA4D9EAA-5122

8 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 -
16685 - Cylinder 1
P0301 - 35-00 - Misfire Detected
16687 - Cylinder 3
P0303 - 35-00 - Misfire Detected
16686 - Cylinder 2
P0302 - 35-00 - Misfire Detected
16514 - Oxygen (Lambda) Sensor B1 S1
P0130 - 35-00 - Malfunction in Circuit
17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 35-00 - System too Lean
17956 - Boost Pressure Regulation Valve (N75)
P1548 - 35-00 - Open Circuit
17585 - Bank2: O2 (Lambda) Correction Behind Catalyst
P1177 - 35-00 - Control Limit Reached
Readiness: 0010 0001

-------------------------------------------------------------------------------
Address 03: ABS Brakes Labels: 8D0-907-389.lbl
Part No: 8D0 907 389 E
Component: ABS/ESP allrad D56
Coding: 04395
Shop #: WSC 06435
VCID: 35614A6A0FA054969D-5122

No fault code found.

-------------------------------------------------------------------------------
Address 08: Auto HVAC Labels: 8D0-820-043-1D.lbl
Part No: 8D0 820 043 P
Component: A4 KLIMAAUTOMAT D58
Coding: 00160
Shop #: WSC 06435
VCID: 2D51620AE7F01C56E5-2584

1 Fault Found:
00787 - Temperature Sensor in Fresh Air intake duct (G89)
30-10 - Open or Short to Plus - Intermittent

-------------------------------------------------------------------------------
Address 15: Airbags Labels: 8D0-959-655-AI8.lbl
Part No: 8D0 959 655 G
Component: Airbag Front+Kopf 1002
Coding: 00304
Shop #: WSC 06435
VCID: 3A7B595626BEBBEE70-5140

2 Faults Found:
65535 - Internal Control Module Memory Error
00-10 - - - Intermittent
00588 - Airbag Igniter; Driver Side (N95)
32-10 - Resistance Too High - Intermittent

-------------------------------------------------------------------------------
Address 17: Instruments Labels: 8D0-920-xxx-17.lbl
Part No: 8D0 920 981 B
Component: B5-KOMBIINSTR. VDO D12
Coding: 02264
Shop #: WSC 09222
VCID: 2B556C12D9E41266FB-5122

No fault code found.

-------------------------------------------------------------------------------
Address 35: Centr. Locks Labels: 8D0-862-257.lbl
Part No: 8L0 862 257 N
Component: CV-Pump, Alarm, RC D16
Coding: 16140
Shop #: WSC 06435
VCID: 408F2BBE4062E13E3E-4ECC

No fault code found.

-------------------------------------------------------------------------------
Address 45: Inter. Monitor Labels: 4B0-951-173.lbl
Part No: 4B0 951 173
Component: Innenraumueberw. D03
Coding: 00101
Shop #: WSC 06435
VCID: 60CFCB3EE0A2813E1E-4B16

1 Fault Found:
01377 - Ultra Sonic Sensor for Alarm System; Left (G170)
27-00 - Implausible Signal

-------------------------------------------------------------------------------
Address 55: Headlight Range Labels: 4B0-907-357-AUT.lbl
Part No: 4B0 907 357
Component: LEUCHTWEITEREGLER D004
Coding: 00012
Shop #: WSC 06435
VCID: 65C1DA2AFF80E416ED-5198

1 Fault Found:
00776 - Level Control System Sensor; Left Front (G78)
31-00 - Open or Short to Ground

-------------------------------------------------------------------------------
Address 56: Radio Labels: 8D0-035-1xx-56.lbl
Part No: 8D0 035 195 A
Component: Radio D00
Coding: 00200
Shop #: WSC 06435
VCID: 2447872EB43ADD1E3A-4AFE

1 Fault Found:
65535 - Internal Control Module Memory Error
00-00 - -

End-------------------------(Elapsed Time: 03:57)--------------------------

[Cyrus221]

I replaced the b1s1 70m ago, and the b2s2 1k miles ago. Ugh. I do have an n75 valve that I was going to replace when I did my tial setup but it looks like I'll have to replace it a bit sooner. The n75 code I had before when I got the car but it was random and didnt show up after I cleared the DTCs ... and here it is again!

Thoughts anyone?

[vavJETTAw36]

You are assuming the sensor is bad. It may be. It may not be. Check the connector to make sure no moisture. Check wiring to make sure it's not chafing anywhere and make sure it's not melted on the downpipes. A vacuum or exhaust leak can also bring about that code. It's a hard one to diagnose because it can be caused by all the other codes and all the other codes can be set by a bad O2.

I'd try swapping the b1 and b2 sensors to see if it follows.


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[Cyrus221]

You are assuming the sensor is bad. It may be. It may not be. Check the connector to make sure no moisture. Check wiring to make sure it's not chafing anywhere and make sure it's not melted on the downpipes. A vacuum or exhaust leak can also bring about that code. It's a hard one to diagnose because it can be caused by all the other codes and all the other codes can be set by a bad O2.

I'd try swapping the b1 and b2 sensors to see if it follows.


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Checked all the 02 sensors for any damage and there doesn't appear to be any, also swapped sensors and it follows. Thank god I have a lift ... that would have been a nightmare on jackstands.

Plan of action should be n75 and smoke test for leaks you guys think?

[airjawed]

You have a tial setup and still have a cat code?

You really need to attack things one at a time... Fix what you know is an issue and then move to the next code. So do the N75 which controls boost(unless you have a manual one)... then fix your misfire(ground wire under coolant possibly?)... then O2 sensor....

[Cyrus221]

You have a tial setup and still have a cat code?

You really need to attack things one at a time... Fix what you know is an issue and then move to the next code. So do the N75 which controls boost(unless you have a manual one)... then fix your misfire(ground wire under coolant possibly?)... then O2 sensor....

Nono -- I have almost all the parts for my tial setup (i only need to do engine work before I put everything in, its currently stock) but they're all sitting on a shelf on my garage.

So I'll do the n75 then i'll go ahead and reset my DTCs and drive again. Fun times xD

[Cyrus221]

Eyyyy. So, back again ... I replaced the n75 and I noticed I had crisper throttle response (is that even a thing?) but now I misfire randomly even when driving. So, B1S1 next? Or any other tests you guys would think?

[airjawed]

Did you change the plugs to stock with 0.024 gap? Did you clean/tighten the ground wires below the coolant reservoir?

[vavJETTAw36]

What's your fuel trims? Measuring block 32 And 33


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