Update. No 02s in and the car runs perfect.how?

[FrankenStang]

I have a 98 mark 8 motor in my 97 thunderbird...mods are: cobra intake cams,ported manifolds, exhaust with no cats or rear o2's,255lph fuelpump no egr , tuner( cant dattalog) and has new spark plugs all propperly gapped, clean mafs and oil, no vaccum leaks or leaks befor the 02 sensors...
Now the problem is when mycar is cold and 1ststarted it misses and pops horribly and i have next to no power, its so bad that i CANNOT drive it untill its warmed up because it seriosly feels like it would shit out...but when it gets warm you hear the whole idle and exhaust note change as if majic and then it runs top notch...its worse now in winter but it did do it in warm weather also...any ideas??????

 

[FrankenStang]

o ya, 02's are 1 year old with maby 7000miles on them, autolite copper plugs are gapped at .52, wires and boots and coilpacks are all good, clean mafs , runs 93oct, 5w30 oil...any of that help?

 

[FrankenStang]

anybody?????????????????

 

[chris91]

Who did the tune on it? I would think its something in the tune.

 

[the.greg]

What brand o2 sensors are they? I always heard to run oem only, but idk why personally.

 

[97FloridaGT]

Clean your IAC real good and then put voltage to it to test it.

 

[FrankenStang]

isnt it always the front 02's that take the reading? and lol when i got the car it didnt even have any 02's onit and it ran just the same, which mabymaby my 02s are bad, they were some ebay sht i got last year...the only codes the car throws is for heated front o2's ( no cat converters) and NO response from rears...no lean codes, idle is good even at cold start but if i get on the gas it just wants to **** up...if it were the iac id be consistant woldnt it? plus i did clean it and tried a iac restrictor ( but removed untill problem is sovled)...its still on the stock thunderbird ecu but with a superchips canned tune, and this motor can run fine on teh stcok tune asis off teh Tbird too btw but lets not go there now..could it be my grade oil? 5w30???

 

[96gtsleeper]

not oil bud. check your pcv hose make sure no rips or if its sucking its self together. also if your still using the tbird ecm that might be a problem too. check vacuum hoses closely though can look good but might not be flowing properly

 

[justinschmidt1]

Rear 02s do nothing...front 02s can make changes but when your car is cold its in open loop and the 02s wont make changes until the car warms up

 

[FrankenStang]

well ima go grab a tps,iac and mafs and change them all and see what happens....

 

[98fobra]

Any luck my 32v swap is the same way

 

[FrankenStang]

..no,no luck...and i swear the copper plugs made it worse...

 

[FrankenStang]

Ok I got it running purrfect smooth idle smooth even power from stop to any speed. But I fixed it by unplugging the front 02 seniors. How can it even run none the less run perfectly!?!