has anybody installed an o2 sensor on one of the header tubes close to the exhaust port? if so which cylinder and did it make a difference. i am noticing my o2 is not giving me the correct readings until the engine gets to the operating temp. and think it is mounted too far (in the collector) from the heads causing a cooling problem of the combustion gases. i do have a heated o2 and it does stay in closed loop.

 

If it gets hot and goes closed loop that's all it needs to do. Do you have a good power source, and ground?.

Be nice to have a clue about what you're working on.

 

4x4 truck

383 stroker, 64cc 23deg trickflow heads c/w weiand xcelerator single plane, adapter, cam is an extreme 4x4 comp. Cam. 12-235-2 grind ( .447/.462 lift, duration 210 218 lift @50, 111 lobe separation) . unit has hypr. Flattop floating pistons, eagle cast crank, 5.7eagle rods. 10.2:1 comp. Headers c/w 2.5” flowmaster exhaust. 16147060 pcm, $85def
454tbi 80lbinjectors

 

If you're concerned about getting O2 values sooner after startup, try going with a heated O2.

 

He already has a heated one...

PR, it shouldn't take more than a minute or so to heat a HEATED sensor up, but, on a cold engine, you'll may still be in open loop for a bit even if the sensor reaches proper operating temp. As Grumpy says, if you reach closed-loop, all is well. If you don't have any operability problems, all sounds "normal".

 

as i said i do have a new heated o2 and i works just fine, my concern is that the headers are cool during the winter months and therefore giving me false readings before reaching engine operating temp. the reason i say this, when the engine is first started in the morning it runs smooth in open loop, once it reaches 50deg c and hits closed loop the blm shows rich. the ecm compensates and leans things up but then the engine starts to run rougher at the same rpm. things clear up when the engine reaches operating temp.

 

that sounds normal pscarf, you need to adjust your coolant correction table for the lower temps

 

then why in close loop does the ve look rich and then when running at normal temp the blm is very close to 128?

 

what coolant correction table, is there a ve for closed loop at for coolant temp? not in my $85def!

 

All the oem sensor does is toggle over rich lean at .45v.
So no things are fine.
If you trying to actually read an AFR ratio with a switching type sensor you need to do further research about how the sensors actually work.