86 chip in a 87??

[mrg7243]

So I really havent posted in awhile but this an interesting question. My dad said back in like 89 he took the car in for a diff fluid flush(he thinks). He also said that they installed a new chip in it. The car is an 87 and from what I have read this is an 86 cali smog chip. Why would this happen? He bought the car as a dealer demo with 1000 miles on it.

The silver sticker on the top of the chip says DELCO CMW 0602 bottom is JT8(g)AF31/p.

 

[TurboDave]

If memory serves the 0602 was an 86 chip. Not sure why they would stick that in there, because there actually was a smog recall chip produced in mid year 87. BBKJ sticks in my mind.

 

[GNVenom]

As I recall, the CMW chip was 86, ACXA 87, and BBKJ was the '89 recall chip.

The 84 was CMM, and I think DMM for 85. I could be wrong on those.

 

[dennisL]

Why the dealer installed the 86 chip (CMW) in the 87 is a mystery to me as well. However, it wouldn't hurt anything and just might be a minor improvement. There are only 6 values different (not counting the prom id & checksum). Five of them slightly change the warm-up afr (made richer), and one makes the PE afr at 133 degF richer. So, perhaps the dealer was just trying to do your dad a favor.