Problem with Shell V-Power Racing gasoline in RS5

[MpDzik]

About a week ago, the EPC light came up on my 2014 RS5 while driving and the 6k RPM rev limiter was activated. Strangely, after turning the engine off and on again the EPC light went off and everything went back to normal. Next day I drove to the dealer service to find out what was the reason for the EPC light and it turned out to be fuel-related. I am tanking Shell V-Power Racing (best fuel I can find in Poland as far as I know) since about 2 months of ownership of the RS5 and I didn't have any issues until now. Today, after one week, the same thing happened - after about 5 minutes of driving the EPC light and rev limiter turned on and then after starting the engine later today the light was off.

The dealer service told me to try other premium-grade fuel to see if the issue persists, so I guess that's worth giving a try.

Has anybody encountered any similar issues?

[ffearless]

I had a similar issue 2 years ago. The EPC light and rev limiter came on 3 different times in10 days. I didn't do anything different and it hasn't happened since.

[SteveRS4]

I had a similar issue 2 years ago. The EPC light and rev limiter came on 3 different times in10 days. I didn't do anything different and it hasn't happened since.

Yes me to had it happen twice after using fuel from the same gas station 1 month apart i never been back there and its never happened since ! Could try another Shell just dont use that station might be the tanks are full of crap !

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[BuyTheWarranty]

I've never had that issue with Shell V Power Nitro+ 91. Are you using 91 octane or 92?

My RS5 seemed to run the 'best' on the Shell, the exhaust note was a bit meatier.

I flashed my car with the JHM 93 octane map last fall, so I'm using Husky 94 (up to 10% ethanol) and we now have Chevron 94, with no ethanol which I'll use in the summer. I believe the RON rating for Shell is quite high (98/99) even though it's only 91 octane and I think Husky, Petro and Chevron are all 101.5 RON in Canada. I've heard that Shell 92 is THE BEST, but not available in Canada.

It sounds like you maybe got a bad batch of fuel, which happened in my S5 from a different gas station. If it continues, your HPFP might be going bad, as that happened to my RS5 (epc, limp mode, wouldn't rev past 6k) and it ended up being bank 1 HPFP.

[MpDzik]

Yes me to had it happen twice after using fuel from the same gas station 1 month apart i never been back there and its never happened since ! Could try another Shell just dont use that station might be the tanks are full of crap !

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That's what I thought too at first when it first happen, however, I already filled up a full tank from another Shell station and it happened again. I will try BP instead of Shell for a while to see if it resolves the issue.

Besides that, the service told me that the EPC light was not exactly triggered by bad fuel. The fuel mixture was too rich or something. Shell V-Power Racing is rated at 100 RON so that makes some sense, however, I can't believe that an RS car wouldn't handle such fuel. I've been using the same fuel for years in my 2005 Toyota and never had any issues.

[MpDzik]

I've never had that issue with Shell V Power Nitro+ 91. Are you using 91 octane or 92?

My RS5 seemed to run the 'best' on the Shell, the exhaust note was a bit meatier.

I flashed my car with the JHM 93 octane map last fall, so I'm using Husky 94 (up to 10% ethanol) and we now have Chevron 94, with no ethanol which I'll use in the summer. I believe the RON rating for Shell is quite high (98/99) even though it's only 91 octane and I think Husky, Petro and Chevron are all 101.5 RON in Canada. I've heard that Shell 92 is THE BEST, but not available in Canada.

It sounds like you maybe got a bad batch of fuel, which happened in my S5 from a different gas station. If it continues, your HPFP might be going bad, as that happened to my RS5 (epc, limp mode, wouldn't rev past 6k) and it ended up being bank 1 HPFP.

Shell says V-Power Racing is 100 octane. In Poland we generally have 95 an 98 octane fuel available. I will try to use 98 for some time and see if the issue persists. I hope not.

[WannaRS5]

I recently started using Shell v-power 91 gas here in CO on my RS5. Have had the car for 1.5 years with no problems using regular 7-11 91-octane gas. I think i got a bad batch of gasoline as well from Shell. My check engine light came on a week or two ago, when i checked the code it stated "Post Catalyst Fuel Trim System Too Lean - Bank 2". Don't know if its related to the gasoline used in the car but seems possible.

I put a new tank of gas in from a 7-11 and cleared the codes, codes have not come back for over 300 miles now.

[hahnmgh63]

Sounds like a bad batch of gas. Gas in one area to the next is all different. Most distributors sell the same base stock which may not even come from a Shell refinery, just the additive package that gets put in it prior to distribution.

[Ape Factory]

If you can, scan for codes and report back. Want to know exactly what codes are being thrown.

There's no way the race fuel is leaded is there? That'll kill your 02 sensors quickly.

[Ape Factory]

Your OEM tune is not optimized for that much octane. The flame propagation front is moving at a slower rate than 93 octane, probably too slow for the ignition schematics contained in the OEM tune. Too much octane will actually make less hp if not optimized for it. I'm guessing you're triggering some sensor, whether it be knock or even throwing off your a/f ratios and expected EGT's.

[JamesRS5]

I have only ever run the car on 98 fuel with no issues (this was recommended from Audi) and I believe we use the same RON rating system as Europe which would be equivalent to 93 PON in the US.
I see little point in 100 RON fuel, you're paying extra for something you won't be getting an advantage from unless your car is mapped for it.

[Overbias]

Any chance you can get a full scan done and report back here?

I will be writing up and adding to the Fuel Issues thread with everything we have learned (Cos and I) over the last few months to get issues like these resolved.

Often we see codes thrown which seem to indicate one thing but we have learned that they sometimes are not actually indicating the true issue.

Best place to start though is a scan with all the codes. Any chance you can share that?


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[MpDzik]

Thank you everyone for your replies.

If you can, scan for codes and report back. Want to know exactly what codes are being thrown.

Unfortunately I do not have the equipment to check the codes on my own. I checked them at the workshop where I service the car. I will ask if they can provide me the specific codes.

There's no way the race fuel is leaded is there? That'll kill your 02 sensors quickly.

No way, it is unleaded of course.

[MpDzik]

I have only ever run the car on 98 fuel with no issues (this was recommended from Audi) and I believe we use the same RON rating system as Europe which would be equivalent to 93 PON in the US.
I see little point in 100 RON fuel, you're paying extra for something you won't be getting an advantage from unless your car is mapped for it.

Your OEM tune is not optimized for that much octane. The flame propagation front is moving at a slower rate than 93 octane, probably too slow for the ignition schematics contained in the OEM tune. Too much octane will actually make less hp if not optimized for it. I'm guessing you're triggering some sensor, whether it be knock or even throwing off your a/f ratios and expected EGT's.

I don't care much about the additional power, more about the fuel quality as I am planning to own the car for a long time. As far as I know, Shell has the best premium fuel where I live. Unfortunately they do not have 98-octane, only the low-budget 95 and V-Power Racing 100.

The EPC issue repeated two or three times last week. This week I didn't get the EPC light, not even once, so maybe it was a temporary issue. I will switch to 98-octane BP ultimate for some time and see if the issue occurs again.

[MpDzik]

Any chance you can get a full scan done and report back here?

I will be writing up and adding to the Fuel Issues thread with everything we have learned (Cos and I) over the last few months to get issues like these resolved.

Often we see codes thrown which seem to indicate one thing but we have learned that they sometimes are not actually indicating the true issue.

Best place to start though is a scan with all the codes. Any chance you can share that?


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Sure, I will ask the workshop where I had the codes scanned if they can provide me with any details.

[BuyTheWarranty]

I don't care much about the additional power, more about the fuel quality as I am planning to own the car for a long time. As far as I know, Shell has the best premium fuel where I live. Unfortunately they do not have 98-octane, only the low-budget 95 and V-Power Racing 100.

The EPC issue repeated two or three times last week. This week I didn't get the EPC light, not even once, so maybe it was a temporary issue. I will switch to 98-octane BP ultimate for some time and see if the issue occurs again.

Are you referring to OCTANE or RON?

[MpDzik]

Are you referring to OCTANE or RON?

It is the RON rating as far as I know, although strangely I cannot find any specification details on Shell's website.

[MpDzik]

I finally got the details on the error codes scan from my workshop. Turns out that the code which triggered the EPC light was P129B00 and previously the fuel-related codes occurred - P017100 and P017400.

However, the problem does not seem to be occurring any more. Similarly to what ffearless wrote, the EPC light came up a few times (4 to be exact if I recall correctly) in the last week of January and the issue has not returned for almost two weeks. I even took the car for a more spirited drive on the highway during the weekend and everything was fine too.

[Steelhead]

This is interesting thread! I have had my RS5 for almost a year now and have always run Shell V-Power 91(?). Never had an issue, until recently had the CEL come on and took it to service and cylinder's 2 and 8 were misfiring. Fixed now, but makes me go hmmmmm!