John, its a 92. I lost the pickup on my Small Car VSS and didn't know it. About that time I install a chip and thought my problem was cured. Almost two years later I discovered the missing pickup, installed the new VSS and had the problem again and realized it wasn't the chip that fixed it. This time when I disconnected the VSS I got the code. I runs fine without the VSS and the idle speed was stable, in park/neutral and correct in drive, but it bothered me that I was now getting a CEL and code 27. It was only when I ran without the VSS and then reconnected it while the engine was idleing that the CEL went away(instantly I might add) and it didn't start running bad, instead it ran like it did without the VSS. For this reason I believe the poor running, the CEL and code 27 and the VSS were related and relates to ECU learning and resetting. It may be that the ECU can learn to work with or without a VSS. Just how to cause that to happen I don't know, nor do I know if this would be the case with all SVX ECUs. I use premium, never tried the 87 octane feature of the chip. Thought I would point out the economics of premium vs. regular.
