its funny you mention the eha,ive been having the same issues with mine,i replaced the old one with a used one off ebay,had the air fuel ration recalibrated,i found the engine runs like crap boggs ,loss of power,pops in plenum,needs to warm up to operating temp.then when i disconnect the eha,the car runs strong has lots of power,does not hesitate does not pop in plenum,but when it sits for about 30-40 mins its extremely hard to start,i assume cuz disconnecting the eha leans out the fuel mix.well the weather is getting colder now,so i may plug it back in and see how it runs in the winter.but it also needs an o2 sensor,i wonder if the 2 work in unisome with one another?