Check engine light, blinking

My check engine light was coming on and off for awhile, but not blinking. I pulled the code and it was supposedly the alternate air pump check valve. I drove it for a while and then I was on a trip and going up a steep grade when the the light started blinking, I tried to get over as quick as possible and get off the highway, but then I got to the top and the light went constant. I pulled the codes again and I got a misfire in cylinder 4 and alternate air check valve. I changed the valves, plugs, wires, rotor, and cap. I tested it again; gunned it until the governor kicked in and the light started blinking again. I'm going to go get the code pulled again this weekend, and if it's a misfire again, whats my next step? Compression check?

Sounds like the trouble I was having with my 96'. After replacing wires, plugs, cap and rotor. Misfire code still came up. I found out it was the fuel pressure regulator. Got it fixed for about $450. I advise having the fuel pessure tested-that might be the problem.

The check engine light blinking indicates that a misfire is happening (while it is blinking).

Fuel pressure test should be performed, as well as, checking the ignition system for issues (includes dist gear which can wear and cam retard setting).

//2000CAYukon

Eh, I guess its time to suck it up and take it in. Thanks for the help guys.

I was getting the misfire on cylinder 5 code on my '96 hoe. I changed plugs, wires, cap and rotor and still got the dreaded P0305 code. I took her in and my mech told me that my intake gasket was bad - just worn after 11 years. He replaced and she purred and the SES light went away. He charged me $400. Good luck...!