S4 Missfire on cylinder 1, 2 & 3?

Lavis89

Well-Known Member
Regional Rep
As per the title, my car has developed a missfire on cylinder 1, 2 & 3 (all of bank 1) I've been running a dtuk box which I've now disconnected (haven't driven it since, that's tomorrow's job) any ideas what could be causing this if it wasn't the box?
 

V6_Man

Moderator
Staff member
Moderator
VCDS Map User
Plugs and Coil packs? Did it go in limp mode?


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Lavis89

Well-Known Member
Regional Rep
It did, wouldn't have thought it would have been plugs or coil, not with all 3 cylinders on the same bank at the same time.
 

Lavis89

Well-Known Member
Regional Rep
Cleared the codes after removing the DTUK tuning box, drove 100 miles or so yesterday on A roads and B roads and the car didn't miss a beat. I'm guessing the car couldn't keep the fueling up to match the increased boost from the tuning box.
 

Dippy

Registered User
Well now you ought to put the DTUK box back on and see if the problem returns...

I have never liked the idea of a piggy-back that just increases boost by tapping into pressure sensors but relies on the ECU to detect lean and increase fuelling. IF it is the box that has caused this then it is a good argument against them.
 

Lavis89

Well-Known Member
Regional Rep
Thats a good shout
 

NikNefedov

Registered User
Had a problem with my DTUK box as well. The gearchanges were awful and when putting your foot down it had about 2 secs of lag. Doesn't matter which setting you were in the problem was the same. Tried to email DTUK but no response. Will have to ring them tomorrow.
 

Dippy

Registered User
I don't want to seem anti-DTUK, but remember that there is a limit to how well any of the simpler type of piggy-back tuning boxes can work. It is relying on fooling the ECU into behaving differently. It can never be as effective as a proper remap.
 

mercules

Registered User
I was having missfires after I installed a transmission mount. Or at least that was the only mod I did and a day later I went into limp under wot. Was on two cylinders I cleared codes didn't come back. I went to MRC for a tune few weeks later Doug showed me the missfire logs which were cleared. My engine pulled about 5hp less than 333hp stock an Doug suggested maybe bad fuel or sparks and mapped I think I was set at one less bar because of it being "weaker".

Few weeks after being stage 2 I kept going into limp one in every 5 hard pulls. I bought new coils and sparks from ngk swapped myself broke some clips but almost 3 months later not a single missfire and car pulls an starts much better than before.

It's probably the tuning box boosting the values of the car and causing old sparks or coils to missfire.

Also my sparks were changed at Audi 18months before I swapped them again but I did also do coil packs to save myself doing it again.

I would get them all changed cost about £200 in parts and couple hours work if you got the tools. Plus it's a service item right at some point in time it needs doing.

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mercules

Registered User
Opie oils were cheapest for the parts I used a 10% discount code they keep chucking about.

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