Check engine And car useing up alot of gass

Hey guys i have a gsx mostly stock with hsk Bov Cat back, and 16g turbo the car has been sucking up lots of gas and it idels really weird it fluxuates the idel and my engine check lights on i added a ne o2 sensor the one near the turbo and another thing when i jump on my car sort of blackish color smoke is comming out im confused om going to read it throught a scanner and tell you guys the codes. thanks

Dude you have got to use periods. Get the cel codes pulled and let us know what they say.

i was gonna say 02 sensor but you allready that, just check the codes, will be alot easier

Um...I think you need a tune/tune-up. Any type of fuel control or boost controller? And no upgraded injectors?

Hey i got the codes. i do not have any type of controllers or injectors the only up grades it hks bov running in atmosesphere, 16g turbo and cat back the codes coming up is a p1400 and p0505. the p1400 is mdp sensor and p0505 is the idle speend can you plese thell me where thses to thinks are located thanks and how much the cost to replace. i also dont understand when you get on my car blackish brown smoke come out the tail pipe. thanks

Black smoke means you are running rich. That vented BOV could be causing you some problems too. I got a few weird codes when I did that to mine, and I would stall out at a stop light if I didn't give it gas. Like said before, a tune-up would be in your best interest. Did you take a look at the plugs?

plugs and wires are good they are pretty new is there a way to ajust the lean and rich or i have to buy a controller? anotherthing how many mpg is a gsx suppose to get? thanks

It varies but 18-21city and 25-28 highway, or in that ballpark. What year is your car?

Hey its a 95 gsx with 87000 miles and running rich dont help