P0300....My Personal Troll of 2016

[mosnet99]

Hey AZers,

Coming to you guys for ideas about my unwavering P0300 code. My car was mostly stock not long ago but what started as a P0299 Control range not reached has ended with P0300. I'll lay down the history on the car. The original P0299 code was from a clogged CAT (150K original), most likely this was probably from prolonged clogged EGR and/or Crankcase ventilation. This even came coupled with a leaky valve cover (haven't got to that yet).

So first thing I did (Before the P0299 code) was swap out the CC ventilation for 034s, cleaned out my airbox, put in a ITG air filter, and a new MAF. Even went as far as changing out all check valves and SJP. After the ITG filter was installed I checked the MAF to make sure it wasn't mucked up with oil and it wasn't.

After that the car was fine for a while, then popped up a persistent P0299 code. Had an Indie shop do a boost leak test for me and found no leak so we figured it was the Turbo or CAT. So I removed both put in a Hybrid K04 and a Milltek HFC. We will skip the aggravating no start situation right after because of the Crank sensor.

Immediately after I started having misfires, my coil wires were cracked but not severely corroded but I replaced them with 034s ignition wire replacement anyway. Still getting intermittent misfires on all cylinders. So I replaced the spark plugs, same. Then I tried to ignore it for a while and went to a state of denial, thinking I would have to replace the whole engine harness.

Then I upgraded the Intercooler for shits because I got a CXR FMIC for cheap. Afterwards the car ran exactly the same and no boost leaks, so pretty sure I installed that right. Came back to reality and figured its about time for coilpacks, absolutely sure that would be the fix I got the ECSTuning 2.0T coil setup with BKR7EIXs.

As you can probably tell by now, I'm still getting random misfires on all cylinders and when I'm logging on VAG, its under load....at idle, when its cold, when its hot. Not immediately at startup but after it warms up. The car still performs well but sometimes I'll feel a stutter in acceleration. I just want a test of some sort to tell me what it is...even if I can't fix it right away I'm tired of not knowing. Can anyone help?

[MurkyRivers_A4]

Have you checked your fuel pressure at idle? Have you changed your fuel filter?

[mosnet99]

Have you checked your fuel pressure at idle? Have you changed your fuel filter?

I changed my fuel filter about 7k miles ago, stopped the pump from whining. That's all. Haven't checked the pressure. Can you just put it on the Schrader while it's idling? And do you know the spec?

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[KHARDa4]

I changed my fuel filter about 7k miles ago, stopped the pump from whining. That's all. Haven't checked the pressure. Can you just put it on the Schrader while it's idling? And do you know the spec?

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Yes. 58 psi.

[mosnet99]

Yes. 58 psi.

Thanx I'll check it today

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[mosnet99]

Yes. 58 psi.

Guess that's not it

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[MoparFreak69]

Check injector wiring. I have seen broken wires do what you are describing.

[mosnet99]

Check injector wiring. I have seen broken wires do what you are describing.

I checked those too. I was only able to see the actual wiring of cylinder 1 but the harness wasn't cracking like the ignition harness was when I moved it around. Are you suggesting removing the plastic from the whole harness?

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[MoparFreak69]

Yes. I've seen them break in spots where the wiring looks perfectly normal and intact until you pull on it. The wire inside was broken but the insulation wasn't. You'll probably have to expose every wire and gently tug short lengths at a time unless you find an obvious damaged spot.

[mosnet99]

Yes. I've seen them break in spots where the wiring looks perfectly normal and intact until you pull on it. The wire inside was broken but the insulation wasn't. You'll probably have to expose every wire and gently tug short lengths at a time unless you find an obvious damaged spot.

I'd rather not go ravaging thru my insulation. I'll do some tugging and moving the wires around but to remove all the insulation only to find everything intact.

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[DarkoNova]

I don't know what the 1.8 wiring harness looks like as I have a 3.0, but I'd imagine there would be a main connector somewhere that connects the main harness to the injector harness.

You could disconnect that and disconnect each injector and test each wire for continuity while wiggling/tugging on each one to check for breaks.

[rocket1420]

I don't know what the 1.8 wiring harness looks like as I have a 3.0, but I'd imagine there would be a main connector somewhere that connects the main harness to the injector harness.

You could disconnect that and disconnect each injector and test each wire for continuity while wiggling/tugging on each one to check for breaks.

That is not an option on a 1.8T. No wiring harness plug. It comes straight from the ECU.

OP, have you checked for vacuum leaks?

[bwizard]

My wife's had the same problem cut the plastic back the harness is screwed from heat I cut hers back to the fire wall and all coil pack wire insulation cracked the length of the valve cover

Sent from my S4's talk to text broke in my garage.

[bwizard]

Then get the harness repair kit for 120$ and some adhesive backed heat shield booooom problem solved

Sent from my S4's talk to text broke in my garage.

[bwizard]

I know that it is all one piece stock but I can't remember there is a company that will send the harness and the 16 wire connector for the Ecu side you wire it in from there you can replace remove as needed

Sent from my S4's talk to text broke in my garage.

[mosnet99]

That is not an option on a 1.8T. No wiring harness plug. It comes straight from the ECU.

OP, have you checked for vacuum leaks?

https://www.youtube.com/shared?ci=CiFUgQlJbRE

Would this show vacuum leaks? I made the a4 darkness cap for the tip

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[mosnet99]

Then get the harness repair kit for 120$ and some adhesive backed heat shield booooom problem solved

Sent from my S4's talk to text broke in my garage.

That has already been done, when I opened up the hard plastic to do this repair I was able to verify that I cut out all the exposed and cracked wiring. My ignition wiring is cut back to around the thermostat housing. So I doubt the wires all the way back to the ECU need replacing.

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[URS4surf]

Have you verified you're injectors to be good? If their stockers you could pick up another set cheap.

When you upgraded were the injectors also done at that time? Seems the timing from your description might point to them....

[mosnet99]

Have you verified you're injectors to be good? If their stockers you could pick up another set cheap.

When you upgraded were the injectors also done at that time? Seems the timing from your description might point to them....

How would I verify the injectors to be good or not? They are stock with 150k on them most likely

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[URS4surf]

Unless someone here knows a good way to bench test them, I believe you would need to send them out to be flow tested/rebuilt.

Where they are stock I would just pick up another set.

I picked up a set of stockers so I can pass inspection for $40 to give you an idea.

you also stated there was oil in your plug wells?? That can definitely cause misfires also....

I finally traced my misfires to an injector this past weekend but mine were almost all on Cyl 4......

[mosnet99]

Unless someone here knows a good way to bench test them, I believe you would need to send them out to be flow tested/rebuilt.

Where they are stock I would just pick up another set.

I picked up a set of stockers so I can pass inspection for $40 to give you an idea.

you also stated there was oil in your plug wells?? That can definitely cause misfires also....

I finally traced my misfires to an injector this past weekend but mine were almost all on Cyl 4......

Well the thing is with a new fmic installed and K04, the next set of injectors I wanted to buy was gonna be an upgrade. Since now I could get a tune since I have a HFC, fmic and upgraded turbo... basically all the requirements.

No oil in my plug wells, never said that.


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[URS4surf]

I made an assumption when you said leaky valve cover....sry

I hear you spending $'s on the upgraded one's.

Do you have anyone local with a 1.8T? you could swap them in <30 mins...

If not, then monitor channel 15-16 while your driving to see if any cyl is predominantly misfiring. then swap to see if problem follows...

[mosnet99]

I made an assumption when you said leaky valve cover....sry

It's actually just the gasket under the CCM or tensioner or whatever

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[mosnet99]

I made an assumption when you said leaky valve cover....sry

I hear you spending $'s on the upgraded one's.

Do you have anyone local with a 1.8T? you could swap them in <30 mins...

If not, then monitor channel 15-16 while your driving to see if any cyl is predominantly misfiring. then swap to see if problem follows...

Problem is when monitoring Group 15-16 I get random misfires on all cylinders. I get the P0300 & P0302. I'll get 1 on cylinder 1, 2 on cylinder 3. Then it'll clear all 0s. Then 2 minutes later 2 on cylinder 2 and 3 on cylinder 3. It's random & intermittent. Very frustrating

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[mosnet99]

I hear you spending $'s on the upgraded one's.

Do you have anyone local with a 1.8T? you could swap them in <30 mins....

I'll try to get a set from the pull a part place near by. 1.8 in Passats should be the same.

I know I can get a set of EV-14s for like $150 so didn't wanna spend $50 on some I won't use long.

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[rocket1420]

https://www.youtube.com/shared?ci=CiFUgQlJbRE

Would this show vacuum leaks? I made the a4 darkness cap for the tip

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No. The vacuum system and boost system are entirely different. Every vehicle has a vacuum system.

[mosnet99]

No. The vacuum system and boost system are entirely different. Every vehicle has a vacuum system.

I have more details. So upon startup I get no misfires. After I let it warm up a bit and start driving I'll get maybe 1 misfire on 1 random cylinder. Then once the engine is completely warm and I've been driving regularly... I'll get to a stop light and I'll feel a stumble, that's when I get multiple misfires on a single cylinder. After the engine is warm I'll be getting random misfires on cylinders but very rarely multiple misfires on a single cylinder until I stop at a light. To me this is crazy. I switched to BKR7EIX .032" gap but seems like better performance on BKR6E on whatever pregap

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[bwizard]

Is it an amb engine? Is your coolant level slowly dropping? Leak down test? Blown head gasket cracked head

Sent from my S4's talk to text broke in my garage.

[mosnet99]

Is it an amb engine? Is your coolant level slowly dropping? Leak down test? Blown head gasket cracked head

Sent from my S4's talk to text broke in my garage.

Yup. AMB.
Coolant level never drops. I did a compression test and can't remember the exact readings but I remember cylinder 3 & 4 not reading as high as cylinder 1 & 2. But they were all within spec. That was like 3 months ago. However, like I said I get random misfires on all cylinders

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[URS4surf]

whichever cyl your seeing the multiple misfires , swap that injector with another one.

Mine would be very random but watching it at idle and driving it was predominantly cyl 4 in my case. I would see single hits on other cyl's but every now and then cyl 4 would pop off up to 100.
but then I could drive a week without getting a CE light.......

I swapped CYL 4 with CYL 1 and now I see the same behavior on CYL 1.

I'm also assuming you have already swapped coil/plug from suspected CYL which is what lead me to the injector's being suspect.

ymmv, good luck

[vjborelli]

What are your readings for Lambda (Actual) when the misfires are occurring? (Channel 30 or 31 I think it is)
And what are your fuel trim adaptations at? (Idle and Partial) (Channel 32 I think it is)

[mosnet99]

What are your readings for Lambda (Actual) when the misfires are occurring? (Channel 30 or 31 I think it is)
And what are your fuel trim adaptations at? (Idle and Partial) (Channel 32 I think it is)

Cruising in 3rd




At idle


Cruising in 4th

Had a friend take a look at it and I believe he said he switched around coils, boost tested and vacuum tested. Some how getting the misfires to go away. Go figure. But he did say he got a p0299 over boost afterwards. He said that could be attributed to the K04 and it's not tuned for it. I guess I'm satisfied with a pretty steady idle now but I took some pics and videos anyway.

UPDATE: On channel 32 my Adapt Partial got up to -7.0%

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[vjborelli]

I believe a -7% Adaptation (Partial) leans toward either restricted air flow, or excessive fuel flow at boost. I could be wrong though.

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[mosnet99]

whichever cyl your seeing the multiple misfires , swap that injector with another one.

Mine would be very random but watching it at idle and driving it was predominantly cyl 4 in my case. I would see single hits on other cyl's but every now and then cyl 4 would pop off up to 100.
but then I could drive a week without getting a CE light.......

I swapped CYL 4 with CYL 1 and now I see the same behavior on CYL 1.

I'm also assuming you have already swapped coil/plug from suspected CYL which is what lead me to the injector's being suspect.

ymmv, good luck

Thanx for this. It came back and it's always on cylinder 2. Swapped it with 1. Now the misfires are on 1 & 3.

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[mosnet99]

Is it an amb engine? Is your coolant level slowly dropping? Leak down test? Blown head gasket cracked head

Sent from my S4's talk to text broke in my garage.

With a cracked head. Would you see full power even under boost with no misfires and only get misfires at idle? I still may want to do a leak down test to be sure of this

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[rocket1420]

With a cracked head. Would you see full power even under boost with no misfires and only get misfires at idle? I still may want to do a leak down test to be sure of this

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When the head heats up, it might expand enough to seal whatever is leaking. I'd definitely do a leakdown test and stop guessing. I got my tester at Harbor Freight for like $35 out the door. It worked great the one time I needed it and paid for itself. Go here to get a 25% off coupon good until December 11th.

[URS4surf]

Thanx for this. It came back and it's always on cylinder 2. Swapped it with 1. Now the misfires are on 1 & 3.

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Glad you seem to have found your issue!

from your description I would also suspect cyl 3's injector.....

Steve

[mosnet99]

UPDATE: Replaced all the injectors with low mileage AWM injectors from 04 Passat. Then I found this on the connector that snaps into the camshaft sensor (I think):




So I replaced that as well. Now I got P0340. Still misfires

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[rocket1420]

That has already been done, when I opened up the hard plastic to do this repair I was able to verify that I cut out all the exposed and cracked wiring. My ignition wiring is cut back to around the thermostat housing. So I doubt the wires all the way back to the ECU need replacing.

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Wait a minute. The injector wiring doesn't run near the thermostat. But the wire for the cam sensor does. Are you sure you checked the coil pack wiring?

[mosnet99]

Wait a minute. The injector wiring doesn't run near the thermostat. But the wire for the cam sensor does. Are you sure you checked the coil pack wiring?

Sorry not thermostat housing I meant I cut the wires back to the coolant flange in the back. The coil pack wiring was replaced with this: https://store.034motorsport.com/harn...wire-coil.html

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