I have 1995 Chevy Blazer 4x4 with the 4.3 V6. It is riddled with problems, but there are two of immediate concern. Check engine light is on. Muffler shop (where I just had a new muffler and catalytic converter put on) ran the codes for me and came up with P0131, upstream O2 sensor; p0401, EGR insufficient flow; and p0441, EVAP system failure to purge. A little background is that so far I have replaced the starter, the thermostat and the offending O2 sensor, plus I had new plugs and wires put in, in addition to the previously mentioned exhaust work.

So, my question now is, which of the two remaining error code problems should I tackle first, the EGR or the EVAP? I am concerned about one or both problems damaging my new catalytic converter. My second question is, where should I start looking first for each problem? Purge solenoid? Charcoal cannister? I dont even have any idea where to begin with the EGR problem! lol I have the Haynes manual, but until I started working on this bad boy the most I'd ever done was change the oil on a car. So, I'm learning as I go.

Thanks, fellas. I'll really appreciate any help.

 

Here is a post with alot of info you can go and find.

https://blazerforum.com/forum/showth...ighlight=fault

 

I had an issue with the purge solenoid not allowing me to fill my tank. Slightly different code and mine was on an '02. Perhaps this thread will be of some interest to you.

https://blazerforum.com/forum/2nd-generation-s-series-1995-2005-tech-41/problems-filling-p0453-32418/