i was driving yesterday and out of nowhere my afr's went down to 11.6. idle and 12.6 cruise.

i thought, okay...the ecu has had enough of my fuel trim antics. so i went and reset the computer by unplugging hte battery. nothing. i figured..i didn't do it long enough, soi just went home and did it again.

waited three hours, tried different tunes...nothing.

took out hte f/ic..put the stock ecu back in...nothing.

still 11.6-10.4 AFR at idle. reset everything. nothing worked.

mr meaty came over and looked at it...unplugged hte o2 sensor...tried it without the f/ic...nothing. unplugged with f/ic...ran a little bit at 14.7...i went down the street and then....nothing.

im stuck at 11 AFR no matter what tune i put on it.


whhhhhhhhhhhhat is wrong!?

 

could it be a boost leak on the cold side? that would cause rich conditions right?

if it's a boost leak it would be sudden...it wouldn't go down gradually as it does right now.

could it be my afr gauge?

 

u can buy my aem uego and give it a try if you want lol

 

It could be a boost/vac leak, what does you boost gauge read?

 

i have one already.. =/

my boost gauge reads -20 at idle -10 cruising and 5 in boost.


just like it should......my car runs fine.....i just think it has to do with the computer system somehow

 

it would start out at 14.7 when i start the car but then gradually lower down into the 11's

all within a minute of starting the car

right now im on hte stock ecu...it should be at 14.7

 

took off all the piping, checked all couplers and vac lines

it's not a leak

right now its still on the stock ecu and slowly drops down to 11.6 afr.

and then stays tehre, never kills the car...just drops...also, my RPMs drop really low too.

im about to take this turbo off and be done with this.

 

your idle is only at -10 vac? that is definitely a leak somewhere. mine is around -20 at idle

 

mine has alwasy been at -10 vac unless i'm remembering wrong

 

yea -10 vac seems low, im at arround -22 vac at idle

 

i was wrong, -20 vac.

it's not a leak, my car i otherwise running fine...

 

mine was doing the same thing in reverse. would start and idle at 14.5ish and then within 30 seconds would creep all the way to 17.9/---

 

watching cuz that crap sounds super weird... maybe check the harness?? maybe a wire is loose.. no signal on a wire... did u check the basics... spark plugs, all vac lines, 02's... just throwing stuff out there.

 

spark plugs might be fouled...but it shouldn't cause this...

ill double check the harness but i think it's fine

o2 sensor might be the culprit but i unplug it and it still does it

maf sensor same thing, unplugged i still get the same result. i hate this.

 

have u tried cleaning the maf and the o2. ...maybe it has alot of carbon build up... its happend to me on the NA...

 

maybe the o2 sensor...havn't checked that yet...would it cause rich though?

carbon build up = cannot sense fuel ratio...does it run rich to be safe?

this same thing happened to you, pete?

 

im very tempted to take everything off again.

sell it or not...i can't take this.

how do you clean an o2 sensor?

 

i had a cell come on for the lower 02.. took it out.. it was black.. cleaned it up a bit with a dry cloth and took off the carbon deposits... (gently)... i blew on it.. put it back... cell was off no worries... its rare that it happens but it does... try that.. also check and make sure all the sensors are plugged in all the way... also do u have any cells??

 

nope, the only cel that comes on is because of hte tune

 

Just try cleaning your O2 sensor - I think I've suggested it already to you.

It's the easiest test right now - it's not logical to disassemble your whole system when you haven't tried all the alternatives (specially the easy ones).