Golf 6 1.4 TSI Random Misfires, EPC.

XxMeantTagxX
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Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Hey everyone!,

My current golf 6 is getting engine management lights and causing random misfires on the diagnostics to show up.
I just got its timing and service done but as it left the workshop it is doing the same as before, if i look at my boost gauge i cant boost past a certain point or else the pistons misfire and eventually EPC comes on. at the most it doesnt get the EPC but it does misfire as a put my foot flat.
My current mods are: Full custom exhaust with decat and downpipe, stealth induction.
Scared to do software as i don't know what the outcome will be.
Any help would put my mind at ease. :cry:
Ashveer03
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

Is "random misfires" the ONLY dtc that you are getting?

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:Is "random misfires" the ONLY dtc that you are getting?

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Yes at the moment its just showing that.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

How did the problem come by? All of a sudden on its own, or after some work(exhaust or intake)?

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:How did the problem come by? All of a sudden on its own, or after some work(exhaust or intake)?

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It came about a month ago. i had the car since october last year and the day i got the car i did exhaust and no problems up until now.
someone said its my cat sensors.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

If u have ur own scan tool and u understand data logs then u can use that to help u find the problem. U can view o2 sensors via live data to see if they are working as it should.

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:If u have ur own scan tool and u understand data logs then u can use that to help u find the problem. U can view o2 sensors via live data to see if they are working as it should.

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i went to get a diagnostics done and they told me what happened but they did mention something about the fuel running too lean.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by hostility »

XxMeantTagxX wrote:
Ashveer03 wrote:If u have ur own scan tool and u understand data logs then u can use that to help u find the problem. U can view o2 sensors via live data to see if they are working as it should.

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i went to get a diagnostics done and they told me what happened but they did mention something about the fuel running too lean.

Bingo.

Common lucky packet 1.4tsi problem.........Stage 1 Software should fix this. Something for you to consider, hit up Tazo and let him have a look.
Especially the recently revised 1.4tsi Revo stage 1 file. :thumbup:
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

Ok so the engine possibly runs lean when floored causing a misfire.. that could lead to a number of problems.. can be low fuel pressure, dirty maf, an exhaust leak, etc..

Since u have an aftermarket intake, i suggest u should take a look at the maf sensor first. If its dirty, u can clean it with some carb cleaner, or a maf cleaner which u should be able to get from a spareshop or a goldwagon.

Where about are u situated?

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

I would also look for any leaks on the induction pipe after the maf sensor

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:Ok so the engine possibly runs lean when floored causing a misfire.. that could lead to a number of problems.. can be low fuel pressure, dirty maf, an exhaust leak, etc..

Since u have an aftermarket intake, i suggest u should take a look at the maf sensor first. If its dirty, u can clean it with some carb cleaner, or a maf cleaner which u should be able to get from a spareshop or a goldwagon.

Where about are u situated?

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i am situated in kloof, Durban area.
i do hear what sounds like air escaping where my bolt on is connecting my downpipe and end piece.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

That section is after the o2 sensors so I dont see that causing the issue but anyway get the car to an exhaust shop to have that checked out.. sounds can be decieving. Any exhaust leak before the o2 sensors will cause a lean condition.

Do u perhaps here the car spool or dump differently? Maybe any louder?

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:That section is after the o2 sensors so I dont see that causing the issue but anyway get the car to an exhaust shop to have that checked out.. sounds can be decieving. Any exhaust leak before the o2 sensors will cause a lean condition.

Do u perhaps here the car spool or dump differently? Maybe any louder?

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with the induction it gives off a good dump sound but where the turbo is situated in the front, that connection between the turbo and the pipe that connection came clean off 6 weeks ago it has been repaired but i think that might be leaking.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

It probably is, sucking in unmetered air. Get that checked out before doing anything else

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:It probably is, sucking in unmetered air. Get that checked out before doing anything else

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just went to the exhaust place and there is a tiny hole near the downpipe
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

Did u get it sorted out? If so, how is the car moving?

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Ashveer03 wrote:Did u get it sorted out? If so, how is the car moving?

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Haven't done the repair just yet but i have confirmed for software so lets see if the software solves the problem.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by BoraMad »

Sounds to me like it could be the "mini-cat\cat fooler", ideally you would want to load software to override that fact that you have a decat DP.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

iirc a faulty minicat WILL give u a cat efficiency dtc, or a b1s2 dtc which he is not getting.

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

Just got it tuned and it shows piston 3 miss firing only so I'm guessing it's the coil

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by THANAS »

Coil/coil harness/plug/injector/injector harness/low compression are the usual suspects.
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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

Swop no3 coil with another and check if the misfire moves

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by Ashveer03 »

Most likely an injector hence the lean condition.. wouldnt a faulty coil cause a rich condition?

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by XxMeantTagxX »

So I spent a lot of money and it was actually one problem....
Spark plugs weren't gapped

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Re: Golf 6 1.4 TSI Random Misfires, EPC.

Post by THANAS »

Ashveer03 wrote:Most likely an injector hence the lean condition.. wouldnt a faulty coil cause a rich condition?

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The misfire results in a burst of unburnt air (and fuel) entering the exhaust which is picked up by the lambda(oxygen sensor) as a high oxygen % which is then interpreted as a lean condition by the ecu.

Glad it was something as simple as a plug gap, I would have though the stock gap should be sufficient! Nice start to the weekend :).
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