Renix O2 sensor on PaceSetter header

[Bobolink]

I've been wondering lately.... From what I read in the Renix MPI manual that I have, the O2 sensor runs most effectively at temps around 600°F+. Since the mounting point on the Pacesetter header that I installed a couple years ago is way downstream from the stock position, I've always wondered if it is being heated adequately by the exhaust. The stock manifold mounting point is of course right up on the manifold itself, whereas the Pacesetter position is on the exhaust pipe, about 18" or so before the cat. I think the ECU disengages the heater relay when it thinks the exhaust temps are adequate for the sensor to function, based on time or engine temp perhaps. I used an IR temp sensor to measure the temp of the exhaust pipe at the sensor location, and it's about 315°. At the collector, bottom of the header, close to where the stock sensor would be mounted, I get about 420°. These temps are at idle, so I'm not sure whether they can be considered meaningful, but I thought I would throw my observations out there for comment. I'm just wondering if my O2 sensor could be working better if I were to have a bung mounted closer to the engine, and if it would be worth the trouble. Everything seems pretty good for a 250K+ miler. 18-19 MPG mixed driving in the winter, 19-21 summer.    

[cruiser54]

You're fine. The O2 sensor heater has you covered. I've done a few swaps with an HO header, using the downpipe as a location point for the O2 sensor with no issues. 

[Bobolink]

Thanks cruiser....I was hoping you'd comment. I've just wondered if it stayed hot enough once the relay opens, since the ECU doesn't monitor EGT and wouldn't know if the sensor was staying hot enough. But you're right, I've not noticed any ill effects since I put a new O2 sensor in a couple weeks ago. Prior to that, I could smell that the exhaust was a bit rich.