Thenextlevel

1995 Z/28 has headers and cam/lifters/rockers. I am fairly certain the cats are gutted, the prior owner told me they were but I haven't checked to verify for myself. The car is getting relatively poor fuel economy, around 10-12 mpg around town. I am easy on the throttle while I drive it. Would the cats being gutted have anything to do with fuel economy?

bowtienut

iTrader: (1)

Nope. No affect on mpg whatsoever.

Thenextlevel

Is there any sensors that monitor the exhaust coming in and out of the cats?

96capricemgr

iTrader: (1)

Was it tuned?
Then was it verified to be tuned well?
Is there something stupid going on like an adjustable regulator?
Is there an exhaust leak between the header and head? That will suck fresh air causing the O2s to read lean and the pcm to dump in more fuel.

ThoR294

iTrader: (6)

no cats wont change your MPG. maybe MPG being dumped into the ozone

Thenextlevel

I have a receipt for it being tuned with the prior owner, but have no other proof that it was done. I will check for a leak with the headers. I know the car has modifications, but I feel like it should be getting a little better fuel economy

96capricemgr

iTrader: (1)

is it a big cam with stock gears lugging all the time?

Intelligently modded and reasonably driven a car's mileage wont suffer much, but a LOT of cars are poorly modded and then assembled even worse.

Thenextlevel

It's a relatively mild street cam, it has a little lope at idle but nothing extreme. The install was done at BnT Performance in North Carolina.