s4awd

For those of you that have Evos, is your tail pipe covered with deep black soot? I just noticed it today on my car. I hear that the car runs rich but I was surprised to see how black the inside of the tip is. My other cars have barely any black soot in their pipes

1QWKEVO

iTrader: (3)

correction the car runs HELLA rich, I datalogged 1.00 volts on the O2, properly tuned cars should be at 0.92-0.94 volts, 0.96 tops.

yycools

iTrader: (4)

yeah, my does that too, as well as my old gsx. Running rich at the top end is suppose to be better for the motor on turbocharged cars right?

gtr

iTrader: (6)

AFR = 9 + (2 * Vlin)?

I'm confused, what is the stock AFR?

twdorris

In the 9.5:1 range up top. Big time rich.

Thomas Dorris

gtr

iTrader: (6)

That's insane

1QWKEVO

iTrader: (3)

Yes... there are different ways to measure it, one is a ratio which is near 9.5-10.0 the other is volts which is how you can monitor it which is 1.00-1.01 volts. Running rich ok but running too right is a performance loss issue, the car should be ran inbetween, not too rich and not too lean.

1QWKEVO

iTrader: (3)

just to let u know if your looking at the ratio aspect optimal is 12.5:1 stock is around 9.5:1 to one

limey

will be paying for my new cat...very rich...black spots on garage floor from start up.....why can't they just tune it properly?

twdorris

FWIW, this is basically the same setup the DSMs have been running forever and a day. I've not heard of a premature catalytic converter failure yet. I'm sure once you get up to cruising speeds and even idling for while, where the A/F ratios hover by design around stoich, things get heated up and cleaned out just fine.

Thomas Dorris

1QWKEVO

iTrader: (3)

cuising speeds are ok, but if you do floor it, and I know everyone does, the car runs beyond rich...

Let me put it like this, 3000gt's are known to run extremely rich stock, the evo runs wayyyyyyyyyyyyyy more then the 3000gt's do. It will plug the cat up in time if you floor the car alot... My cat is commin off man for all you F&F fans and ricers go throw a spark plug on ur tip $50 says you'll throw fire stock

SouthernCrane

iTrader: (1)

Mine gets black really fast. I posted about this a little while ago, here is the link: https://www.evolutionm.net/forums/sh...mper+get+black

1QWKEVO

iTrader: (3)

Probably to save Mitsubishi's @$$ since they don't like to warranty things.....

N10S

iTrader: (4)

I notice mine running real rich too. Exhaust tip reminds me of a chipped VW or Audi.I also noticed a lot of idle stumble today like its loading-up a little. If I rev it a bit it cleans-up, but I am thinking the rich stock AF/R may be contributing to this problem because the car still runs great.

I wasn't planning on doing an SAFC immediately, but if this trend continues I may have to. Thats my story for my wife anyway