tchesney87

I have a 01 sentra with the QG18DE block and I am wanting to buy some headers for it. But all the headers I have looked at has only 3 places for the sensors and my car has 4 sensors. Why is this and what can I do?

sentratron007

what brands of headers are you looking at ? obx makes one hotshots makes one and there are allot of headers on ebay that have four 02 sensor plugs. three on top and one on the bottom.

tchesney87

the ones i am looking at are the OBX headers. What brand has four holes?

sentratron007

from 01,02 need four and from 03 up only needs two plugs. obx should have three plugs on the header itself and the fourth plug needs to be welded on the down pipe. i have an obx on my 03 sentra.

tchesney87

ok thanks for the info. Just one more question... since there are two sensors after the cat on the factory manifold, by putting the two on the header that was after the cat, would it change any performance since the exhaust wont be as clean as it was with the cat when it reaches the two that was after the cat?

sentratron007

your ses light should turn on. the mechanics at nissan told me that it turns on becuse it reads no diffrence in the change before and after the cat . the odd thing is that my light turned off after about two months after the header was installed.www.b15sentra.net/forums/showthread.php?t=124886this will help you with the install .