[oil pan 4]

My friend with a 2.7L 2000 toyota tacoma put a header on after his exhaust manifold cracked and he failed inspection. After trying to get a used manifold for 2-3 weeks his fail sticker was about to run out.
The dealer wanted $440 for a new manifold and pacesetter had headers that fit his truck for $160.
He does not like to modify his truck at all, for what ever reason he belives in keeping vehicles 100% stock (other than tires and rims) even tho he is a mechanical engineer and always complanes about how manufactures cut corners to save a dime.

His results were he picked up about .5mpg after switching to headers.
The factory manifold wasn't a bad design, it looked alright to me.
I modified the header and extend the O2 sensor harness, it had the same setup where the O2 read off one tube. We agreed this would not be ideal for fuel economy. So I plugged the sensor hole on the tube and installed an oxygen sensor bung in the collector.