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
by bud_ice in Pittsburgh, PA on March 09, 2009
ANSWER by Russ , March 13, 2009
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.