AMTEXX

I have been using an octane booster for some time and definitely notice the difference in hp/tq, but I keep ending up with this red soot at the end of my tail pipe. My dad runs the same one in his CTS-V and gets the same thing.

Too rich/too lean? Anyone know what this could mean? Thanks in advance for your help.

Shazam321

iTrader: (1)

I think it might be the type of fuel you are using. (ie 7-11 vrs chevron) try using a higher quality fuel like shell or chevron.

AMTEXX

What's crazy about this, is that I've only used Chevron premium since I rolled it off the lot. I refuse to get gas anywhere else.

It's so difficult to drive my car without the booster in it, because it is a completely different car. You guys should try it. I'll post the link to the one I use....but seriously do you think I might be hurting it? And no....I just can't drive it like a grandma, uh, unless my wife is in the car complaining about my driving.

http://www.permatex.com/products/aut...ng_Formula.htm

AMTEXX

Thanks for the info! I'll definitely stop using it, and................of course I still have my cats......yeah, I would never think of removing those.

caterpill

iTrader: (11)

I think it may mean that the octane booster you use contains MMT. Often used in octane boosters, MMT leaves red soot deposits like you mention. Not very good for your o2 sensors or cat.

AMTEXX

Do you think it's harming the engine though? It's so hard not to use this stuff because the car runs so much better!

caterpill

iTrader: (11)

Well it is an approved octane booster but simply put, it fouls catalytic converters. If you are catless then you shouldn't have much to worry about besides shorter o2 sensor life n' such.

There are a few articles of MMT around, a quick search on google would net you some information for which to base your decision on continuing to use it or not.

Sorry, I have no real data on which to give you advice on. I have no experience with octane boosters in general.

AMTEXX

How would I know if my O2 sensor went out? Would it start stalling or something? I've never had that happen. Thanks

caterpill

iTrader: (11)

Not sure exactly but I believe you'll set a CEL and fuel economy would probably suffer.

JazWRX

MMT is a manganese based compound. Other octane booster contain Iron compounds. The red soot might just be Iron Oxide (rust). Just a guess from a chemist.

meilers

You're harming the engine in the long run, because you're confusing the crap out of the ECU, to the extent software can be confused. The "learning" behavior of the ECU is constantly adjusting (by very tiny amounts) your timing and spark advance as well as a/f mixture all the time, in response to cylinder conditions. The octane booster is allowing the ECU to advance timing, but I'm willing to bet your mixture of octane booster and gas isn't consistent and thus the ECU is constantly advancing and then pulling timing in response to small detonation events that you probably can't even hear. I'm also visualizing that same iron oxide dust on every surface of the inside of your exhaust system, including valves, header and turbo. Do an internet search for a gas station in your area that has 93 and put the real stuff in it, not the booster, IMO. Or get it tuned to make more power on 91, I've got no problem running Shell Vpower.

charlesj

Most octane boost do cause that red soot you are speaking of. I used to use octane booster in my skyline as it was tuned for 100 octane, however it would foul the plugs (turn them red) after a couple thousand miles making the car run like crap. There are a very small handfull of octane boosters that work without side effects like this and they tend to be expensive and from race gas brands.

In general, don't use octane booster. If you are having problems with 91, either get your car retuned, or mix in some super high octane unleaded.

Also, if you see it in your exhaust, its probably also time to change the plugs

AMTEXX

Thanks for the info guys.

Any idea how I would find a gas station with 93 octane in CA. I've only been able to find 100 octane, but it's so expensive!

Thanks!

meilers

Fuel mixes and additive mixes (such as people who dump tolulene in their tank) are a nightmare, because you don't drain the tank dry every time you put new gas in. I have a 16-gallon tank in my WRX, but the gauge reads E at 13.7 gallons, which means I've got an extra 2-3 gallons sloshing around in there which I never burn up. Now, if I am putting in an additive, a percentage of that additive is going to stay in that leftover gas. Over time the concentration of the additive in the tank reserve is going to build up and become more intense, and that gas mixes with the new gas you put in. I groan every time my co-worker talks about how he stops by a local 76 and puts a gallon of 100 in his Grand Prix (heh!) to turn the "89" into "93" -- yes, I've sent him to several sites which explain gas grades, octane ratings and How Combustion Works, but he's determined to remain ignorant on the topic.