car won't run

[csu15919]

i'm kind of a new kid here. i've had my 01 boxster s for about a year now, 67k on the clock. i recently replaced my clutch, flywheel, all that good stuff. i installed a lightweight flywheel, and it took me sometime to get used to the chatter, and the whurring sound (once the throttle is released). to get to the point...the other night i went out, laid my foot in the throttle for about 3 miles, got off at my exit, and the car died...a friend and i pushed the car to the nearest parking lot, where i was able to pop the clutch and get the car to start, but, if i didn't keep my foot on the throttle, the car would just die. initially, my oil gauge read that i was about 1qt low, so i grabbed some oil and tried to start the car....no go. we pushed the car a little more, and i was able to pop the clutch again and tried to drive it home. about 2 miles down the road, my buddy calls and tells me to turn it off, my exhaust is glowing cherry red. mind you, as i was driving, the car would struggle to get over 4k rpm (i could only keep the car in 1st or 2nd gear). i haven't taken the time to get under the car yet, but i'm just trying to find out if anyone else has had an issue like this before. the only other thing i did differently with the car, was install the deluboz headers (roughly 1 week ago when i finished the clutch job). for the car not wanting to start once the key is turned, i'm assuming there's a sensor issue somewhere (i have a good feeling i melted an o2 sensor with the exhaust getting so hot). well...i'd appreciate any help and/or suggestions.

-stephen