by aesc » Tue Sep 06, 2005 1:08 pm
Yes you should get the o2 sensor put into your extractors. An exhaust place will do it for you no worries. What I did was I got the exhaust place to cut the sensor flange out of my standard exhaust and weld it into my aftermarket exhaust. Wouldnt bother putting the std manifold back on. I think on blue tops the sensor is actually located on one of the primaries, but if I was you, id try get it put into the collector part of them (so further down the exhaust a bit - that way your getting a reading for all 4 cylinders and not just one).
Yea the std 4age exhaust manifold is suppose to be pretty good, but i cant see it being better than extractors although some ppl will argue that.
Without an o2 sensor, yeah it probably is causing it to run a bit rich and therefore rough during idle and could be causing it too run rich during acceleration which is losing you power.
EX AE101 owner
2013 Ford Focus ST