Flashing Check Engine Light w EPL Tune and APR DwnPipe

[JBA87]

I have EPL Stage 2 on 2017 Audi S6 and APR Downpipe on OEM Sport Exhaust. O2 spacers were installed but I still threw a CEL. Recently I noticed some strange issues including:

1. At WOT usually from a roll power delivery will momentarily stop bear 6000/rpm before resuming and then CEL will start blinking.

2. When driving around town with moderate throttle car will have trouble accelerating and exhaust will sputter a little. CEl will star blinking.

Any idea what this could be caused by?

[AudiTechS4]

sounds like misfiring , not sure if epl uses the flashing check engine light for anything it their tune like knock detection .

id contact epl and see about using the flashing check engine light for something . if they dont get a scan and see what cylinder is misfiring

[JBA87]

Also I just did a hard acceleration and again maybe in third or fourt gear at around 6300 rpm car was like "stuck" in gear and would not accelerate or shift to next gear for about 10-20seconds .. then it "clicked in" shifting and continued. CEL started blinking again. This was all with accelerator fully pressed down.

[AudiTechS4]

i would probably stop doing that since you voided your warranty and are possibly damaging your vehicle

[JBA87]

I haven't voided the warranty


But I am curious what the issue is

A cylinder mis fire seems to match the symptoms.

How do I fix


I'm taking to shop Thursday

[Welterweight]

If you’re tuned you have voided the Audi warranty to my knowledge


2014 S6 Black on Black
EPL Stage 1 ECU/TCU
20" Avante Garde
Resonator Delete
Magnaflow Sport
CETE Lowering
RS7 Intake
35% Tint

[pez81]

If you’re tuned you have voided the Audi warranty to my knowledge


2014 S6 Black on Black
EPL Stage 1 ECU/TCU
20" Avante Garde
Resonator Delete
Magnaflow Sport
CETE Lowering
RS7 Intake
35% Tint

Only if the car gets flagged with the TD1. Not a guarantees loss of warranty. Enough people here who haven't theirs.

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[JBA87]

The car is not flagged

[nick1980]

Proper spark plugs and gaps?
Flashing light always meant misfires to me

[SubaruSTI8]

sounds like a misfire not tune issue.

either plugs or coils

[GlacierS5]

If you’re tuned you have voided the Audi warranty to my knowledge


2014 S6 Black on Black
EPL Stage 1 ECU/TCU
20" Avante Garde
Resonator Delete
Magnaflow Sport
CETE Lowering
RS7 Intake
35% Tint

As other stated, TD1 will flag your warranty to be voided. My car has a stage 1 tune (ECU/TCU) and recently flashed it back to oem for a smog the dealership performed. Passed with flying colors. @OP there's a posting by another member who used BD purge oil products that took care of his misfires.

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[OlyS6]

I have EPL Stage 2 on 2017 Audi S6 and APR Downpipe on OEM Sport Exhaust. O2 spacers were installed but I still threw a CEL. Recently I noticed some strange issues including:

1. At WOT usually from a roll power delivery will momentarily stop bear 6000/rpm before resuming and then CEL will start blinking.

2. When driving around town with moderate throttle car will have trouble accelerating and exhaust will sputter a little. CEl will star blinking.

Any idea what this could be caused by?

Not sure which spacers you used, but the j-shaped spacer by vibrant, using the the restrictors with the smallest holes seem to work best to keep you from throwing CELS. The errors with CAT inefficiency seem to also have some downstream effects in terms of other errors. Would recommend ensuring that is working first.
Since you have EPL, you can flash both ECU and TCU back to your stock files and make sure you can drive around without CELs once your spacers are set properly.
Finally, if you don't have one, DEFINITELY get a VCDS cable from Europaparts.com ($199 for a 3VIN cable), so you can do some diagnostics and clear your codes.

[JBA87]

If it's a misfire I hope it's something as simple as replacing plugs/coils and not something more serious

Why would these go out so soon

I have 10k miles ok car

[seandon_792]

If it's a misfire I hope it's something as simple as replacing plugs/coils and not something more serious

Why would these go out so soon

I have 10k miles ok car

Tuning adjusts your air, fuel and spark to create more power. Increasing these things accelerates wear on each of those components. The price we pay to for more performance.


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[rhinoboymtl]

I have been dealing with some similar issues but I’ve finally had a bit of luck resolving it so I figured I’d share. About 1,200 miles or so ago I was due for my 75,000 mile service (which I did myself) which includes spark plugs. Since I was doing the plugs I also decided to change out all of my coil packs and go Stage 1 EPL tune at the same time (why not right?). Even with everything stock I had been feeling stutters and logging misfires since I got the car about a year ago. So I figured now was the time to get it all done.

So I went with Bosch plugs (IKH24) and gapped them at .024 but admittedly I did not take the time I should have nor did I have the best gap tool at the time so I think they ended up varying between.024 and .026. In any case, in went the plugs and coil packs
IMG_4074.JPG

and everything was running much smoother than before. A couple days later I received the stage 1 tune and flashed the car. Went for a drive and almost immediately started with some pretty bad misfires which were audible along with the sputters at low RPM. After the first 100 miles I had quite a few misfires.
IMG_4120.JPG

I did let the car adapt for about a week and put 1000 miles on it and it was strong but still missing sporadically at low RPM. Then when I was pulling away from a stop at about 3/4 throttle I got the flashing CEL along with more audible misfires so I checked my OBDEleven and had 3 hard misfires

IMG_4218.JPG

The day after that I had another in cylinder 4 that was static and would not clear and was causing some nasty vibration at highway speeds.

Time to get this fixed.

I flashed the car back to stock and cleared all the DTCs then drove for about 10 miles and checked the misfire count. Cylinder 4 was definitely a problem.
IMG_4248.JPG

Bought another set of all new plugs (this time NGK) and some proper gapping tools and took my time gapping them. But this time I gapped them down to .022 instead of the .024 some are recommending. With the added boost and air density of the stage 1, I don’t think .024-.026 is tight enough. Removed the old plugs and sure enough cylinder 4 insulator was smoked.

IMG_4251.JPG

Put everything back together and re-flashed the stage 1 tune. Took it for a spin and WOW! No more sputter, steady low end power, no audible misfires and the oil temp actually showed a couple degrees cooler while driving around. I let it fully warm up and gave her a few WOT runs and the power is smooth and strong. No more hesitation or sputters. This car has never been this smooth since I got it even when bone stock. Got home and checked the log....

IMG_4254.JPG

Perfect!

I know these cars have a lot of smarts and self adjustment in the engine, but I’m pretty convinced that some of these misfire issues may be caused by basic plug gaps that are too big for the amount of boost being generated. I know with a smaller gap you might get a slightly lesser combustion and possibly a little less power, but I’ll take the smooth low end power, no sputters and no fried plugs over that any day.

[kpriv]

Great info, thank you for posting. Pretty impressive before/after. How many miles have you logged misfire free?

How did the plugs look on cylinders 5 and 3? For reference, I have a very similar misfire count per 1k as that would indicate (about 225 per 1k miles on cyl 5 and fewer on the others). I never feel it and from logging they almost exclusively occur in low rpm / low load situations.

I’m on original stock plugs right now. Planning to switch to the new OEM ngk plugs when I get around to it.


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[rhinoboymtl]

Great info, thank you for posting. Pretty impressive before/after. How many miles have you logged misfire free?

How did the plugs look on cylinders 5 and 3? For reference, I have a very similar misfire count per 1k as that would indicate (about 225 per 1k miles on cyl 5 and fewer on the others). I never feel it and from logging they almost exclusively occur in low rpm / low load situations.

I’m on original stock plugs right now. Planning to switch to the new OEM ngk plugs when I get around to it.


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I put about 30 miles on last night all over the range of throttle and loads with no misfires. That’s significant for me since I haven’t been able to get even 10 miles of normal driving without a stutter or misfire since I got the car last June.

The other plugs all looked ok. The only one that had a static fault was #4 which was the bad one.

[rhinoboymtl]

Just following up after a couple weeks and about 600 miles here are my misfire counts
IMG_0072.JPG
The car is still running much better than before since I went with the smaller plug gap, but still getting the occasional shutter. It’s strange... seems to be intermittent and not dependent on engine temp. Some days it’s wonky, some days it’s great! Going to keep looking into this a while.

[1975audi]

Just following up after a couple weeks and about 600 miles here are my misfire counts
IMG_0072.JPG
The car is still running much better than before since I went with the smaller plug gap, but still getting the occasional shutter. It’s strange... seems to be intermittent and not dependent on engine temp. Some days it’s wonky, some days it’s great! Going to keep looking into this a while.

Subscribed.
Great info

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