Hello, and thanks for advance for any help. 93 s-10 blazer 4x4 vortec w/150,000 miles. I know this is a long post, and my first here. Truck has been in the family since it was new. Everyonce in a while a piece of carbon will get stuck in the EGR valve making the truck run terrible, and get terrible fuel economy. Remove valve, clean out carbon from valve reinstall, and back to getting unimppresive average fuel economy of 14mpg. This has been done about four times over the past couple of years, and to my knowledge the intake has never been removed and cleaned. Truck seems like it has a miss at idle. Also, the exhaust tends to smell like rotten eggs, which correct me if I am wrong, is caused by excessive unburnt fuel entering the CAT. It does not hesistate when accelerating, and I've never seen the CAT get red hot, and does not act like it is plugged, that is until EGR valve gets stuck open. So question is: Will removing and cleaning the intake improve prevent the carbon from entering EGR, and also improve average economy? Is carbon build up in the intake like this normal for a vehicle with approximately 150,000 miles? Literally small chunks the size of a finger nail are entering the egr valve and getting stuck. The truck just passed emmisions inspection here in Wilmington NC, and also has new exhaust from the cat back. I have a new egr valve to install, and have run seafoam through the intake via the butterfly valve at air intake, but if i need to remove and clean intake properly, I would like to do so, with any tips or pointers that may help smooth the process. Lately all i have owned is diesels, and before that 67-72 chevrolets, so i am not familiar with the more modern gasoline engines. (yeah, haha i am calling 1993 modern) Thanks alot! John

 

You can get a screened EGR gasket to prevent debris from sticking the valve open. You can also clean the EGR supply tube out with a brass pipe cleaner and some carbon cleaner.

As far as your rotten egg smell and poor fuel economy, I would look at the possibility of a fuel leak internal to the engine. The CPI engines are notorious for FPR and/or nut-kit leaks. A quick fuel pressure and leak down test would tell the tale.

 

The intake tube on my 94 Blazer Vortec was so plugged up with carbon, I had to take a small chisel, brushes and a bunch of B-12 to clean it out. 100% solid blocked. Got it that way. Ran a whole lot better afterward. I'm thinking about the screened gasket. Next time I have it off, I'll try it. Engine has about 185,000 miles on it.

 

The rotten egg smell, and poor gas mileage could be a clogged catalytic converter. Also, the last time I changed EGR valve, I sprayed carb cleaner into it, used a wire brush, and started it while the EGR was off and revved it up, and blew out carbon chunks... Worked great. Screened gasket works great too!

 

It definitely could be a clogged cat that is affecting the performance, but most of the time, catalytic converters just do not melt. There is an underlying problem (fuel leak?) that accelerated the destruction.

 

Can I remove the EGR valve completely never to use it again seems like a pain in the *** to me.I'm tired of messin with it