Thanks. I searched but couldn't find it on here. Found it earlier today on Autozone's website. I don't have a full feature scan tool, so I can't go through the full diagnostic check that I have seen online.

 

Oh my goodness. At my wits end with this POS.

I changed out the EGR valve for a new one. At first it seemed like the Blazer was cured but less than 4 miles later, I had hardly any power. The engine will not rev past 3000rpm. The idle can be a little rough but smooths out. I can barely make it to 40 mph. The engine is running super hot (I heard fluid boiling!!).

No codes!

 

Hitting a wall with engine RPM sounds like a restricted catalytic converter. You can try removing one of the upstream O2 sensors completely from the truck and running it. It will set a code for that sensor, but if the truck runs better, then the problem was a restricted exhaust.

What was your engine temperature as displayed on the dash during this period where you heard boiling fluid? Hopefully you did not cause further problems.

 

I don't recall the engine temperature reading at this time. I killed the engine as soon as I realized something was going badly wrong!

The suggestion on the cat sounds like it could be on the right track. I did have a cat code come up way back but I don't recall the trouble code. Will dig a little to see. EDIT: Found the code, it was a P0420.

Now, removal of the o2 sensor - is there an article on here on how to do that?

 

Just disconnect the electrical connection and remove the O2 sensor. It threads into the exhaust pipe. You should be able to get a regular open end wrench on either one of them before the catalytic converter.

 

swartlkk,
Not been able to disconnect the sensor - it's on there pretty darn tight so waiting for some muscle to show up (the boyfriend) to get the little guy out of there.

Side comment - When moving the Blazer around before jacking it up I noticed that as I revved the engine, I could hear a sound kind of like running water? (imagine the noise you hear when water comes through a pipe from an upstairs bathroom only quieter) This noise disturbed me a little but no fluids on the ground. The only other thing I have is a bit of a stronger exhaust smell coming from the front end.

Also to get the Blazer started I now have to give it a little gas otherwise, no fire.

Will update once I get the darn o2 sensor out.

 

The water fall noise is typical of a low coolant level and/or a restricted heater core.

 

Coolant level is good and I should add that the heater in my Blazer works really great.

 

I would still flush the core to be sure.

 

Greetings!
Update: I pulled the o2 sensor before the converter. Drove the Blazer around for a while. Got her up to operating temp and ran around a few hills. Apart from sounding like a NASCAR (:-D insert evil grin here) it appeared that she was pulling like a champ. No obvious stutter, or loss of power. I'd like to test some more but I fear I'll get pulled over for noise. No overheating issues either. Popped a code, (not had a chance to check it) but I'm assuming that is the o2 sensor being missing.

I've located a new Magnaflow direct fit cat for $155 delivered. I'm going to grab that in the next few days. Anyone have any experience with the Magnaflow? I know that sometimes direct fit might still be a little tricky to get in there. I'd like to just put her up on jack stands and change it out myself.

The only other thing of concern at this point is needing gas to start. Seems to need it more when cold than warm. Is this airflow related too? Or something more sinister?