Careful you don't wind up with the clamp screw indexed where it interferes with the O-2 sensor or one of the turbo studs.
A trick I used to make sure the hole would be located in the best spot was to take a worm gear clamp the same size as the one supplied w/the t-couple and measured the hole distance from the screw and then center punched the extra clamp at the same spot.
I then drilled the correct size hole in it and put it on the header & turned it till everything cleared. Next I checked for
clearance for the wrench needed to tighten the clamp and the drill.
When it was positioned good, I drilled the hole with the test clamp in place using the hole in it as a guide for the bit.
Be sure to use a sharp bit (cobalt if you have one) and plenty of oil or the stainless header will work harden & eat up the drill bit.
O2`s sensors aren`t the easiest on a TR to replace, especially when they`re hot. What I did was put the EGT probe in the O2 sensor bung (nut type)and welded a bung on the downpipe about 5 inches from the turbo (3 inch ATR downpipe) and intalled the O2 sensor in the downpipe. Any metal shavings that could be there will be blown out the exhaust ``after`` the turbo.
I can now change the O2 sensor in two minutes. Comes in handy at the strip just before a race when you suspect it`s contaminated.
Steve, I use a Delco AFS 74 heated O2 sensor. I put the combination together this way so I don`t have any before/after comparisons, but I sure go through the sensors quickly with C16. Any suggestions on how to prolong the life of these little devils while using C16 ?
Other than using a MaxEffor chip and pulling the sensor out.....it seems to help to turn the key on for about two minutes before starting the engine. This allows the element to get hot and reportedly keeps the lead from sticking so easily. You might try it and see what happens.
Thanks Steve, as simple as your answer is with respect to turning the key on for two minutes before starting, I haven`t been doing that ... Duh, I should know better. I do have the MaxEffort 16 pos. but I like to check the O2 readings to support my EGT readings, they rarily do.
Could you help me to understand more clearly
the O2`s role with a stock ECM at WOT . It is my understanding that the ECM ignores the O2 messages at WOT. Does the system automatically go into open loop under WOT or just override the signal in closed loop. I`m talking about using a regular style chip, not the ME. Is there detailed desciption of the ECM`s operation somewhere in our archives ? Do you have an address ?
There is an archive there somewhere of all the mailing list activity. Almost any of these types of questions have been answered at one time or another. I haven't subscribed to the list for a year or so now.
but I doubt they offer the aspect you are looking for.
It is my understanding that the ecm goes into a defacto open loop at wot altho the scan tool does not show it to be so. Rather than learning from the o2's input, the ecm commands a fuel curve that is fixed. I am not how this curve relates with what the blm's have "learned". I know that a stock chip will tend to adjust the fueling to offset changes in fuel pressure whereas some of the aftermarket chips have been locked (blm15?) to prevent this from occuring.
I have been using ME's for so long that I tend to ignore most of the conventional chip stuff unless it is something pertinent such as tps voltage settings.
I have been using the same O2 sensor since Sept. 1999, seriously. My car has seen plenty 110oct, 112oct, 114oct fuel. Pure stuff sometimes. I use the MaxEffort chip, which doesn't require the O2. I have never taken the sensor out, even when I add the race gas. I think the MaxEffort doesn't even monitor cross counts, which in turn makes it impossible for the O2 to throw a code. I have been able to tune the car just fine with the same O2 this whole time. The O2 sensor will still read just fine. I think when the sensor throws a code with a regular chip, it senses that the cross counts are getting lazy. Then the first thing you do is replace the sensor, to make the chip happy when in actuality, the sensor is slow, not dead.
BTW - It's a Bosch from AutoZone and it was $19.99
Sounds like a few of you guys would actually save money in O2 sensors by purchasing a MaxEffort!
your input is much appreciated. Looks like we got way off the original topic of EGT installation that ES posted, however a lot of knowledge has been made available. Just when I think I'm getting smart, someone comes along and helps me to realize how much I have to learn ... the good news is,I'm coachable .... I think !