I just bought a 1999 blazer, after a week or so the check engine light went on. Ran the code and it came up EGR Valve. Checked the valve and it appeared like it was recently changed, not much carbon at all, cleaned it anyway, and reset the code. good for a day or so then the engine light came back on again. This time i switched the EGR valve with on from my other blazer (was working perfectly) this was good for a few days. Now the engine light is back on again. Im a little stumped. could it be clogged EGR ports? or something else? how do i clean the ports? where are they located.
any help would be appreciated. (I forgot to mention the blazer runs fine even with the light on, no apparent problems).

thanks

 

What was the specific code?

 

didnt write down the code, would hate to just guess. I'll check it again today and get back to you.

 

Here are three of the codes on the EGR:
P0401 - Exhaust Gas Recirculation Flow Insufficient Detected
P0404 - Exhaust Gas Recirculation Control Circuit Range/Performance
P0405 - Exhaust Gas Recirculation Sensor A Circuit Low

 

hi

checked the code last night. I made the assumption when it went on that it was the same code i was getting all along. To my surprise it wasn't, new code was 410, (secondary air injection system). Just coincedence I guess, truck runs fine with light on. what does it do? I'm guessing I'll have to change my injection pump? not familiar with this at all.how hard is it.
thanks

 

Run a search for "P0410" and you should find the diagnostic sheet & other threads where members have dealt with this code.