Whats up folks? Im a newb here so dont make too much fun of me... Im pretty good at this stuff but I am in need of some help.

I have a "91 S-10 Blazer 4x4 4 Door with 220,000 mi and second engine. They only replaced the longblock and I am slowly replacing the rest. The water pump and radiator went out so I replaced pretty much the whole cooling system and flushed all that happy rusty crap out of the block and heater core. Now here is the problem that was occuring before and now after.

The Blazer runs rough
has no power (feels like something is holding it back... dogs out under load)
gets hot when driving but not too hot as I put a 180 thermostat temporarily and new cooling system
If I stop at a light/sign, the temp will reduce
when feeling the exhaust, It feels restricted, a bit moist, and pretty hot for what is coming out

Now I think it is the Catalytic Converter. Any other suggestions?

Could it be the O2? Maybe the EGR? How do I time it properly?

This baby has some life left in her... as soon as she stabilizes.

 

Cat could be the problem. Beat on it, does it rattle? If so, replace it.

It could also be an O2 sensor has failed or is failing, how is your fuel mileage?
Unplug your O2 sensors and see if the engine smoothes out. If so, replace them. Your puter will go into a default mode and your fuel mileage will drop drastically, but the engine will run good.

Post up what you find out.

 

I have the same issue right now...my front pipe is being replaced today.

It definitely sounds like it could be your cat, but I wouldn't restrict it to just that part of the exhaust system. Do you hear any leaks in your exhaust at all? If you do, it might be that the cold air is messing with a sensor.

I don't feel like it's the EGR...you'd probably be stalling out or close to it if it was that.