Calvin,
Dun lah say things like that. =p No question is too small wan la... everybody's learning. I can help I sure help wan... we all still brader brader although I'm ex-4G91 mah. I still will share share knowledge wan. =)
Btw, narrowband O2 sensor memang cannot get accurate readings wan la. It'll oni tell u if its rich or lean. It can't give u accurate readings wan... just estimate only, thats why its called a narrow band, it only detects a small range around 14:1, anything out of that range is labeled very rich or very lean. =p
Wideband sensors have a wider range of accuracy, therefore it can give u better readings away from the 14:1 mark... but wideband sensors are expensive and have very VERY limited lifespan. Thats why people only use it for dyno tuning or track racing to log your engine performance during the race. wideband sensors lasts between 50-500 hours only... depending on the petrol u use and the tuning. LEaded petrol kills the lifespan, running too rich also shortens the lifespan extensively.
Oh, and I'm not joking. I'm driving 1.3 only now... u dun believe, we go out yumcha, I let u check under my hood, if 1.3... then u belanja me teh O ais + nasi lemak la.... leng mou? hehe... old man di mah. =(
Tajul,
GSR and 4G67 are totally different engine designs lah... what would u wanna do with a 4G67? You can plonk in a GSR block yes la... for 4G67 u need the whole halfcut man... =p nothing's gonna fit your 4G67... cept maybe your radiator. That also ur radiator hoses u mite need to change. haha...