afc ....

[ooljima]

i vent my bov and i have intake and catback...... my gas mileage is like 19 miles to the gallon now when it was 23..... and i see a big plume of black smoke when i romp on it...... will the afc help my gas mileage and get rid of that black plume?.... any suggestions?

[Spectrum]

Nope, put your BOV back to the way it came.

[FourG63 97GST]

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[kjewer1]

Venting the BOV will only hurt AFR when you shift. UNLESS the BOV isnt strong enough to stay closed at WOT. I had no problems running vented for years, but I made sure that thing was staying closed when it was supposed to be. I didnt care if it ran rich on shifts, youre not putting down any power if you arent in gear anyway... And like I said in your other post, exhaust should not affect this. You are either venting a very weak BOV (like the pos 2G one or a banjaxed 1g, or an aftermarket set too loosely) or your o2 sensor is on its way out. If you have access to a datalogger or scan tool, be sure there is no code for it, and that it cycles between .2 and .8 volts rapidly at idle.

[ooljima]

how can i check if my bov is leaking @ wot?

[kjewer1]

It will act like a boost leak. If you are an expereinced tuner you'll be able to tell that its richer than it should be. If its open a lot it will stumble and misfire. But its when its just open a bit that its hard to tell. If you are running a crushed 1g valve you should be ok up to about 20 psi. Maybe higher, but after that it gets sketchy and you have to look at it case by case.

[TEAM KLR]

The Afc Will Help Your Gas Mileage And Black Smoke, Only In The Hands Of An Experienced Tuner. Gsxracer Is Correct On The Bov Subject, We Have Many Fixes For That Problem. We Can Also Install And Tune The Afc For You. Private Message For More Info