okay, i'm thinking that running with open headers could be the reason i'm having some problems. the car idles great. no misfires or anything. as i'm driving down the road i can have it in 4th gear or whatever and go to give it a little more gas and its starts stumbling (for a lack of a better word) real bad. i can then downshift into 3rd, it will still stumble for a few seconds, then with a little more gas it smooths out. and it is running way rich. i went through about 3/4 a tank of gas in 40 miles. it only does this as i'm driving. so the only thing i can conclude is that this is because the o2 sensors are so far back on the headers and i have no other exhaust. of course i went to get exhaust put on today, but no shop had the time to fit me in today to do the welding. so ill have it done tomorrow while i'm at work. just wanted some advice as to if this could be the root of my problem. thanks guys.

 

I suggest you check your oil for fuel contamination and change your plugs. After you get it back of course.

 

i just finished building it though. the spark plugs are brand new ngk's (tr55 i believe). and i finished the engine yesterday and did my first oil change earlier today so there is no way of checking it now. how would the fuel get into the oil anyways? basically, what would cause this and how would i fix it?

 

It could definately be your O2s. What happens is that they read some of the air coming back into the headers and sense that as a lean condition(extra O2). To compensate, your pcm dumps more fuel into the motor.

 

yeah, thats what i was thinking. i guess once i get the full exhaust on, ill find out for sure. thanks guys.

 

ya i was having the same problem with my cut out i changed the plugs and it was awsome afterwards hell ran even better imo