A/F Ratio Issue

[Dmgamerbadk]

Hi i am currently in process of buying a built eclipse gsx and the afr doesnt read at idle but when driving after about 4thousand rpm the afr begins to read. Any idea of fixes without retuning the ecu. It has the stock ecu in it, but comes with a 1995 EPROM. Here is cars mods:
5 speed trans
LSD in rear
Less than 1k on head (Was stripped, cleaned and new stock internals installed)
Black/Tan interior w/ tan leather in great shape (no rips or tears)
MHI Big 16g turbo
Hard intake tube with K&N filter
Poly motor mounts
ARP head studs
ARP turbo bolts
Cometic MLS head gasket
Magnacore 10mm wires
NGK BPR7ES plugs
VRSF Short Route FMIC
Greddy Type RS Bov
Fidanza lightweight flywheel
Brand New stage II Clutch
Aeromotive FPR
Walbro 255lph fuel pump
3" Apexi downpipe
3" Apexi N1 turboback exhaust
1995 EPROM ecu
Triple A-pilar gauge pod
Oil PSI gauge
AEM wideband
Boost gauge
B&M short throw shifter
Brand new MOMO leather shift knob
Aluminum radiator with dual slim fans
3 piece strut bar set
Mitsubishi timing belt
Gates alternator & power steering pump belts
190 amp High output alternator
Lowering springs
Mint GSX wheels with Newer Continental tires 75% tread (plasti dipped matte black)
Tinted taillights
Powdercoated Valve cover, fuel rail, L/R motor mounts & turbo housing. (Illusion violet)

 

[gofer]

The tune has nothing to do with the WB issue, what do you mean it doesn't READ until 4k? Are you saying that the gauge is black (no power) to 4k or it sits lean (20:1) until 4k then it starts reading a richer AFR?

I'd be concerned about the no name "stage II" clutch. FYI, some AWD DSM's came stock with LSD rear ends so it isn't an upgrade and it's more than likely a 90A alternator.

As far as the WB problems, if it's reading lean until a certain RPM I'd assume a bad vacuum leak (if the car idles like crap) or an exhaust leak before the WB sensor if the car idles fine.

 

[Dmgamerbadk]

The afr gauge sits at --- (blank) untill around 4thousand rpm then i reads fine. So basically the isle of the car is terrible and wanta to shut off so maybe ill explore the vacume line issue

 

[gofer]

If the car's idling fine when it's displaying "---" then I'd suspect the WB o2 sensor, if the car's idling like ass when it's displaying "---" and then you rev it up and it comes down (richens up) then I'd say the car's got a pretty significant vacuum leak around the TB/IM/fuel injector seals.