AFR goes from 10 to 20...Whats wrong???
#1
On The Tree
Thread Starter
Join Date: Mar 2005
Location: Kansas City Area
Posts: 166
Likes: 0
Received 0 Likes
on
0 Posts
AFR goes from 10 to 20...Whats wrong???
Using the wideband, when driving, i am going from 10 pig rich to 20 dangerously lean. At idle, its fine, stays around 13-13.5. The orginal 02's are still in. They only have 9k on them however, i cannot find a simple way to test them. I am not even sure this is what the problem is. The maf is good, everything else is new and i am stumped.
#4
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
So you have an LC1 with an XD1 guage?
When's the last time you calibrated the sensor with the ground wire?
Have you check the grounds?
Are you sure there are no exhaust leaks?
Where is the WBO2 in relation to the NBO2's?
Did you change anything in the tune or is it completely stock?
When's the last time you calibrated the sensor with the ground wire?
Have you check the grounds?
Are you sure there are no exhaust leaks?
Where is the WBO2 in relation to the NBO2's?
Did you change anything in the tune or is it completely stock?
#5
On The Tree
Thread Starter
Join Date: Mar 2005
Location: Kansas City Area
Posts: 166
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by SSpdDmon
So you have an LC1 with an XD1 guage? Yes
When's the last time you calibrated the sensor with the ground wire? I did a retest yesterday.
Have you check the grounds? Yes
Are you sure there are no exhaust leaks? Yes
Where is the WBO2 in relation to the NBO2's? The WB is in the X pipe in the place of the rear 02 on an LG header set up.
Did you change anything in the tune or is it completely stock?
When's the last time you calibrated the sensor with the ground wire? I did a retest yesterday.
Have you check the grounds? Yes
Are you sure there are no exhaust leaks? Yes
Where is the WBO2 in relation to the NBO2's? The WB is in the X pipe in the place of the rear 02 on an LG header set up.
Did you change anything in the tune or is it completely stock?
I have checked, rechecked and checked again for leaks in the intake track and exhaust and it is buttoned up tight. I went as far as doing a smoke test on the exhaust looking for a leak and nothing anywhere.
I thought it may be the maf but it checks out fine, the only thing i have not replaced is the 02's and i am holding off just because of the cost for the heated units and don't want to spend two bills on something that maybe working fine.
#7
TECH Resident
iTrader: (17)
Join Date: Sep 2004
Location: NC - Charlotte area
Posts: 3,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by ceo44
mild adjustments on the timing and alot on the injectors because they are 42#.
also, where is the wideband at? put it up towards the collectors (right after them). i think you said you had it in the x pipe... something ain't right.
what are the specs of the cam? and has the WIDEBAND itself been tuned to be read in the software you are using??
either this is something simple as hell and you aren't thinking of it...or somethin's really f***ed up, lol.
Trending Topics
#8
FormerVendor
iTrader: (9)
Join Date: May 2003
Location: Jacksonville, Fl
Posts: 1,573
Likes: 0
Received 0 Likes
on
0 Posts
Have you tried swapping the LSU4 sensor (part of the LC-1)? A hairline crack on the pump cell can give you false readings like you described. Reads fine at stoich/idle, give it any gas and it says you are bone dry lean 20.
#11
TECH Enthusiast
iTrader: (26)
Join Date: Mar 2004
Location: Long Island
Posts: 589
Likes: 0
Received 0 Likes
on
0 Posts
I think you may need to have your tuner go back through the tune. I have the same symptoms when I turn my maf on. When I'm in SD (maf off) my A/F (using LC1 wideband) stays exactly where I tuned it. Now I'm starting to tune my maf from scratch and I get the exact symptoms you're talking about with the maf on. It almost sounds like the tuner tuned it for idle and WOT on the dyno and didn't do enough for the driving around. I'd check the maf tune.
#12
TECH Addict
iTrader: (10)
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes
on
0 Posts
Does it show a 20:1+ AFR while you're giving it gas or only during decel? If it's just during decel, that's probably DFCO kicking in. The other I'd be concerned about is misfires. Misfires will shoot unburnt fuel and oxygen into the exhaust. The sensor will actually read the misfire as a lean condition.
Last edited by SSpdDmon; 04-18-2007 at 11:14 PM.