on my 3.1 mod's are listed in sig

i'm running way rich i'm talking about like 130 miles out on a full tank of gas rich......................

as a result i've burned away the insides of the new high flow cat i just installed now b/4 you ask this was like this even b/4 the headers

i've just changed the o2 sensor & fuel filter
i've been told by several pepole that everything checks out ok
and that it's that way b/c it's a performance car

so i'm back here to the 3rdgen guru's I gone to several shops and still have no idea what or why i'm losing so much fuel any idea's

what do you all think??????????

 

Weak ignition??
Leaky injectors?? Grab a fuel pressure gauge, and put it on the car, prime the pump (put the key in the on but not start) pressure should be around 40 psi. If it drops quickly (to 0), you have a leaky injector. It should stay at 38 and slowly, very slowly, decrease.

 

I agree; check out the fuel pressure. You can do a balance test on the injectors if you buy the injector tester from http://www.sunpro.com 's garage sale links, but you'll also need a fuel pressure gauge.

Could also be that your plug gap is way out of spec, or your ignition system is weak. Might even have a bad spark plug wire somewhere. How's the exhaust smell?

As to mileage, I should track my mileage on a full tank and let you guys know what it is. Lets just say I fill up every 5 or 6 days, and just do around-town driving. 'Course, I still have that one leaky injector...

 

I would have to say bad spark some how/wear. With all them mods, you should have already upgraded spark.

Check cap/rotor
Plugs
Wires
Pickup coil
Ignition Control Mod

A fubar cat will cause poor mpg ontop of the others.
Clean the IAC also.

I belive mine gets around 275 on a tank, more when on the interstate. I belive I pulled easy 330 on 3/4 of a tank going to oklahoma few weeks ago

 

Also, have you modified your intake system??? You need that too.