My blazer runs good for a bit but then its like the engine revs up and down slightly and seems like its going to cut off and it does some time. I checked the codes and it says egr and o2 is rich. I have replaced the spider injector so that should be ok. The ? is? Could she be running ruff till the egr messes up and gets stuck open and is that why the o2 says it rich and makes it run funny? If i replace the egr would it stop the o2 from saying its rich also?
EGR problem and question on 1992 Chevrolet S10 Blazer
Your surging engine may very well be related to your EGR problem. I would suspect the valve is faulty but you will need a scan tool to confirm this. If you find that the valve is bad replace it and see of the O2 sensor code comes back. If it does you could have a faulty O2 sensor also.