DropTopBird

iTrader: (17)

I just got my wideband sensor installed for my AEM wideband sensor today. When I start the car up it hangs around 15 for a second but then shoots up to 18 and then goes to ---. When I drive it bounces anywhere from 14.9 to 17.9. I know its been a little lean since I put the LTs on, but I dont think it should be doing that. Does anyone know what would make it fluctuate like that? My best guess would prob be an exhaust leak, but Im not sure. Thanks a lot.

DropTopBird

iTrader: (17)

Bump....Someones gotta know whats going on with it.

SSpdDmon

iTrader: (10)

If you have your AIR pump still hooked up, that will account for the lean readings after startup.

Once it's up to temp (assuming your still running in closed loop), the PCM will fluctuate fueling and measure those fluctuations via the short term fuel trims and NBO2 sensors.

DropTopBird

iTrader: (17)

So would this be a normal occurance on a car with a stock tune? The air system was deleted when I put the headers on. Im almost positive I knwo where the leak is on the header so could that be making it lean out to almost 18?

SSpdDmon

iTrader: (10)

Possibly. 2000's have been known to have lean issues and sometimes KR issues too (most aggressive timing table of all the years). I'd work on getting the exhaust buttoned up and see where that puts you. It might be a good idea to start considering a tune....or at least a tuning device so you can adjust fueling yourself.

DropTopBird

iTrader: (17)

Yeah Im going to get a full dyno tune when I get my LS6 manifold and p&p throttle body on. I honestly didnt think that just headers and tsp duals would drop the afr that degree. Im pretty sure my friend has a handheld that I can use. If that one leak doesnt fix the problem, could there be anything else that generally causes a lean condition like that?

SSpdDmon

iTrader: (10)

An upstream/vacuum leak can since it would be a source of unmeasured airflow. Generally speaking, you would have had the manifold/throttle body/pcv system off the motor for that to happen though - sometimes things don't go back together as well as before they were taken apart (usually human error).