proper tuning w/o cats?

[stangracer281]

So after replacing my stock h-pipe with an off road verson sans cats.....the car wont run right. The computer is defaulting to a full-rich fuel strategy, even with the stock oxygen sensors in place on the aftermarket pipe. Anyone know how lean out the fuel to get things running properly again?

 

[slvrbullIT]

did you get mil eliminators?

 

[03-s281]

Are you sure you dont have a leak or something.
I couldnt imagine it running too rich just from that.
Whats makes you say its running rich anyway? Whats it doing?

 

[stangracer281]

I havent tried the MIL elminators yet, ill have to give that a shot. Its pretty obvious that its running rich, you can smell it in the exhaust, the spark plugs tend to foul at idle and w/o cats, the sensors detect more free oxygen in the exhast and are tricked into thinkin the engine is running lean. I was also thinking of a custom tune chip, i dont know if that would completely fix the problem.

 

[jrc_03_gt]

you have to have the mil eliminators. GET THEM NOW!

 

[twogts4us]

I havent tried the MIL elminators yet, ill have to give that a shot. Its pretty obvious that its running rich, you can smell it in the exhaust, the spark plugs tend to foul at idle and w/o cats, the sensors detect more free oxygen in the exhast and are tricked into thinkin the engine is running lean. I was also thinking of a custom tune chip, i dont know if that would completely fix the problem.

The smell is likely either the lack of cats or the OR pipe 'breaking in' by burning or baking the finish... New exhaust systems tend to smell a bit funny til broken in. But more likely, if you think you smell gas, it's just from the lack of cats.

 

[03-s281]

The only thing the mil elim do is prevent a code.
They do nothing for the performance. If you dont have cats your gonna smell carbon monoxide anyway. Thats why they are there.

 

[triggz]

fyi, you can make your own MIL elims for under $10.

 

[COramprat]

The only thing the mil elim do is prevent a code.
They do nothing for the performance. If you dont have cats your gonna smell carbon monoxide anyway. Thats why they are there.

Right...I've been running my car without MIL eliminators for about 6 months with no adverse perfomance effects.