I recently did a dpfi to mpfi swap on my 1989 hatchback. All of the info I found on this forum made it really easy to get done. First off let me tell you about the parts used. I bought a 2000 model d16y7 engine and a 1989 mpfi intake without a fuel rail on it. I found a ps9 ecu that I modified for use on my manual trans car. I did the conversion but instead of using a set of injectors off of a ealy model I used the injectors and fuel rail off of the 2000 model motor. In all of my reading I found that I wouldn't need a resistor box with these injector. Everything went fine on the wiring for the ECU and once I added the ground strap back on to the engine she fired up and ran. The problem is that after it runs for a few minutes the CEL comes on. It is always a O2 sensor (1 blink) code. I replaced the O2 sensor in the process of trying to trouble shoot this but it didn't help. It never starts up with the code but soon after the light will pop on. Is the OBD0 ECU causing a constant rich condition due to the mismatch with the new style injectors? The car gets excellant mileage on the highway (42- 48mpg). But in town it only get 25 mpg or so. The only major problem with having the light on is that it idles poorly and you can feel a slight miss when you are out on the road. Under accelation it runs like a bat out of hell. I'm hoping that in fixing this that it will (a) improve my mileage (b) get the idle smoothed out (c) get rid of the highway miss.