I just replaced my CPI spider assembly in my 92 S-10 blazer. I had 273,441 miles on it. About 2years ago I thought I was going to be replaced but turned out that fuel regulator was leaking. The past 2 months my milage was down to 17 mpg from 23/24. Took me about a little over a hour and half to take out the old one and put in the new one. Used about 2 cans of engine degreaser on the uppper intake and the lower intake. Man that was just flat out nasty carbon mess!!! Any way took about 3 cranks and about minute of reving it to clear out all the engine and carb cleaner that was remaning in the ports im guessing. Drove into town and it was just smooth no more rough idling and most of all NO Service Engine Light!!!! Will post my fuel milage latter after I run 2 tanks thur it. I drive 27 miles one way to work and only 2 stop signs and 2 traffic lights to go thur so its a good 98% highway miles. Got CPI unit from Autowharehouse for 189.89 send in my old unit and it comes out to 159 and some change. Tools needed a 7mm socked, 10mm long socket, one straight slot screwdriver and one Torx bit cant remember size and that was it.