About a month ago a warning light came on, and since I was heading thru my dealer's area I had it checked. They said 02 sensor error from putting in race fuel (MS109, varying from a couple of gallons a tank to full-tank for the track).

Well, warning light is back, and I don't want to run the three hours to the dealer every time this happens. Car sounds and drives beautifully.

Any suggestions?

 

tune?

From what I understand, running anything over 92 octane is pointless without a tune. I'm might be swiftly corrected.

 

How did they know you added race fuel? The dme really can record that info...

 

The car is tuned and modified to 720HP/750 race fuel. All done at EVOMS, and the car is fantastic. The tune is designed for 93 octane, and since that is not available in my area I add a couple of gallons of MS109 (unleaded, of course) to get 91 pump gas up to a tank of 93. On track days I run straight MS109. The latest time the light came on I had just added a full tank of 91 pump on a road-trip.
There is nothing here that should be bad for the engine, to my knowledge.

 

You won't really have any real gains from race gas unless you have open exhaust and sport cats with race gas performance flash file. Unleaded race gas can't hurt anything however it does seem to crust up the O2 sensors a little earlier than normal if used regularly, sometimes tends to make the car a little more sluggish as it burns slower and cooler. If it is leaded race gas, this will damage cats and O2 sensors. Hard to say if it was the race gas or just a flakey sensor or little corrosion on O2 plug connector but if it was brought in with race gas still in the tank it would be clear from exhaust smell alone to the tech.

If you want to continue running race gas and if the fault is racegas specific, you could get the consumer version of Durametric and clear the code yourself. For that matter, a generic scan tool would probably work for that purpose as well though will not give proprietary fault codes.

 

Sorry- didn't see your post while writing- disregard.

 

Any idea what was the fault code number present?

 

How do I get the fault code? I would be happy to ignore this is if I could be sure that there is no other reason for the fault light to glow...

 

Depending on the fault (ie manufactuere specific, non-emissions relevant), any generic scan tool found at an autoparts store should give a basic P-code(s). Other wise you could go to an independant shop in your region that has a Durametric pro version scan tool or PIWIS factory tool, or you can visit the dealer (who has PIWIS). They should tell you what the fault code is in P-code and proprietary code. Get the fault code and i will be glad to cross reference it for you. You could also get a basic version Durametric scan tool that will work with your lap top and read/clear codes yourself (i think the basic version that will work on up to three cars (it logs your VIN**) is around $300.

 

here is what I have to reset my CEL warnings from my aftermarket exhaust. The CEL comes on about every 6 weeks, and takes less than 1 minute to reset it.

Actron CP9410 PocketScan Plus OBD II Code Reader

http://images.google.com/imgres?imgu...a%3DG%26um%3D1

 

I used the same thing back when I had another exhaust. This scanner works great, reads the codes and erases them. But, the only sure fire way to stop CELs is with a different exhaust. the tubi works great on a cab, no CELs ever.

 

Thanks for the tips! I just ordered the OBD II......

 

OT, but this doesn't sound right. Which exhaust is this (if you don't mind sharing)? They can't suggest a permanent correction?

 

I'm also interested to know which exhausts will produce e CEL code. Evoms? Switzer? AWE?

 

Everything modded is by EVOMS (EVT 720). Fuel varies from 91 pump to full tank of MS109 (unleaded only). The pocket scan reads the following 5 codes: P2097, P2099, P1095 pd, P2097 pd, P2099 pd. I reported these to the dealer, but haven't heard back yet. If they are only emission codes related to the wide range of octane, I'm happy to just clear them. But I don't know that to be the case. Car drives perfectly fine.....
Some of the earlier posts made it sound like race fuel could be a warranty violation- is that so???