I built a performance EA81 with GD's SPFI conversion. One thing that really made a BIG difference was switching from the stock 1 wire O2 sensor to a 2 wire sensor (signal and ground wire) and grounding it right to the block. The 1 wire sensor was not getting a good enough ground through the exhaust system. This simple mod improved idle quality and performance quite a bit.

 

Don't know if it will help anyone but it is simple to do, cheap, and should work with any single wire o2 system.

I have run a wire with a sheet screw from the heat shileds to the ground wire on the trans. what do oyu order for to get a 2 wire o2? sounds like a good idea.

Yes that does seem a good idea - what part number did you use for your 2-wire replacement? I imagine any generic 2 wire sensor would work so it's down to cost and ease of install....

 

GD

Sorry, I'll update with the part number tomorrow. I think it was an older GM unit. I just chose one with a ground wire to the shell and the signal wire out the center (0-1 volt range). I cut the plug off and extended the leads with solder and shrink tube. I also cut out the OEM connector, replaced it, and shrink tubed that as well. The contact seems to be able to slip out of the end of the factory connector very easily when they get older. Really improved drivability in my case.

I'm happy with my 3-wire (heated) Bosch on my SPFI.

http://www.amazon.com/gp/product/B000BZI4KC

Even better yet! I have a couple 3 and 4 wire ones I could have used but I wasn't positive about wiring up the heater circuit and in too much of a hurry to look it up. Did you just run 12 volts to it, does the heater voltage (usually controlled by the vehicles PCM I think) run on a timer or constantly? Thanks for the ideas.

I wired it to be on whenever the ignition is on. Cheers!

The one I used is a Standard SG3. I like the idea of the heated one too.