Do SCFI fuel systems relif the pressure automatic or would I have to bleed it? I'm going to be changing my fuel filter soon.

About the o2 sensor I misspoke... When I was at autozone I asked one of them to look in their computer and I was told 4 but maybe I misheard or they were wrong.

So far thanks for your help and I cant wait to get my hands dirty this weekend because the blazer isnt doing to good right now

 

The best way I have found to relieve the fuel pressure is to pull the fuel pump relay and start the truck. You will still get some fuel leaking out when you remove the lines from the filter, but it won't spray out. Other ways to do it include wrapping a cloth around a screwdriver and poking the schrader valve in the fuel feed line behind the TB. You'll have to remove the cap first. But fuel will spray out when you do this.

 

Since it was the weekend it was time to get my hands dirty...I know I was talking about flushing the heater core but I knew I had to replace it when the steam/smoke can through the vents. Let me tell you that doing this job was the biggest pain in the a** thing I have ever done. For only a $60 part it took me a good 8 hours to get to it! Probably another 2.5 hours putting everything back together. Haynes repair manual didnt help at all. I ended up having to remove one bolt going through the evaporator case which required me to remove the wheel well etc etc.

oh... When I started I had a check engine light on and when I finish I had a service 4wd but no engine light. whats up with that.
Im just happy its done