I have a '98 A-4 and added a set of LT's and an ORY. The car is running rich and my brother had a MAFT laying around so I figured I would used it untill I get tune. I know a MAFT is just a tempory fix. What setting did you use to lean it out to offset the rich condition caused by the headers? I just want to see what work for other people to get me in the ball park for a couple weeks.Thanks for the help.

 

If you're using it to fix an O2 sensor problem then
you are chasing a ghost.

If you have proper fuel trimming and things are
stable then you probably want to leave base alone
and go about -8% on the WOT wheel (trying to get
from about 11.7:1 commanded, to 12.7:1 AFR
commanded).

But knowing -why- the current rich condition, and
how much / how consistent, would help you a lot.

 

I dont have rear o2's anymore. Everything I read says with headers an an ory the car will be pig rich....The car feels like a dog......I doesnt seems like I picked up anything from the headers. ( I may have but It doesnt feel like much) I will dial in the afr when I get a tune but I want to wait untill I put a cam in it before I get a tune. I have the MAFT for free so I figure I could use for a little while. I figured other people have done the same. I will try the -8% on wot and see how it works. I figure plenty of people have used this of offset the rich condition from the headers and if enough people let me know what worked for them I could get my car in the ball park. Thanks for the help.

 

When I had my MAFT, I had the base 10% lean and WOT 4% Rich. It netted me 13.2:1 on the dyno.

 

what were you mods when you had to set it to 4% rich at WOT. I would think you would have to go lean it out if you have headers?

 

anyone else?

 

I've thought about using a MAFT since I put headers on, since I don't have easy access to tuning.
I think you really need to log some data with a scanner to dial these things in,every car responds a little differently.
FWIW, mine is fairly rich at idle, the LTFTs run anywhere from +1 to +5 at cruising speed, and the O2s run from .910 - .920 @ WOT. And my gas mileage has dropped some.
I'll be watching to see how it works out for ya, I might try one.

 

I had LT's, airlid and descreened MAF

 

I known it kinda outdated compared to getting a tune but mine was free so I figure i'll try it out. My brother also has auto tap so I will try to do some logging (time permitting) this weekend and see where I am at. I did read a post that said just go to the track and see what works best. I may end up doing that. I thought I could get it in the ballpark if I could find out what other people did........I guess there are not to many people who use them anymore but I'll let you know how it works for me as soon as I figure it out.

 

It rained friday night so I did not go to the track.......also my brother went out of town so I couldnt do any logging.....no luck this weekend but i'll post up as soon as I can with some results.

 

All cars are different, headers dont make all cars run rich. I remember reading somewhere that if you go leaner on the base setting, it will also lean out the WOT some. Not sure if that is accurate or not though.