420a sputtering

[Jorge Garza]

So after installing new headers on my 97 rs it had this problem where it starts sputtering and acts like it wants to stall at low rpms in 1st-3rd also is it because it cut off at the midpipe?

 

[VelocitàPaola]

It could be. I'd put my money on a problem with one of the oxygen sensors. Is the upstream sensor installed and working? What did you do with the downstream sensor?

 

[Dsm724]

In my experience with my car unless you run both o2s its going to either lean it way out or its going to run super rich. I also had this problem when I was straight piped an o2 bung helped a little but I ended up going to a full exhaust system cat and all and it got better. Question for you though... are you running an aftermarket fuel pump?