98 Yukon P0300 being caused by clogged EGR?

[OilBurner2003]

Hello everyone! Took my Yukon to the mechanic after trying to troubleshoot for 6 months, he said the MAF sensor, PCV valve, O2 sensors, were all a cause for this P0300 so I got it all replaced. Still have a P0300. So, I started doing some digging. Realized I could smell a lot of fuel fumes at idle, Replaced ignition coil, (I did it because I had it in the shop anyway) A lot better! Almost no fuel smell, but still, P0300. Had someone say I should check my EGR, to see if it's clogged. Below is the EGR side to the engine, I don't know much about these, But that looks pretty gummed up to me. Is there a way to clean this safely? I'm soaking the EGR valve itself in carb cleaner for a couple hours, I'm pretty sure with how gummed up it is it may or may not make a difference, and I might need a new one anyway! But for the engine, which is this picture, how the hell do I clean those ports?


A important note. I can't get this code to appear at idle at all, this code will only appear when you are accelerating hard. I have other posts about this same code, So any advice on how I get that crud out of there is very appreciated. Thank you!

 

[B-train]

Short of pulling the intake, not many options. You could try a vacuum with a small pipe to get in there.

 

[OilBurner2003]

Short of pulling the intake, not many options. You could try a vacuum with a small pipe to get in there.

That’s exactly what I did. After cleaning the EGR and doing a resistance test, everything looked decent. Still have a P0300. In my attempts to find the problem I decided to pull my BRAND NEW ac delco wires out and each wire I pull, is cracked…Gonna swap all the wires again I suppose and go from there.

 

[OR VietVet]

Want to do it once? Pull intake and clean as best as can but sometimes the aggravation is a PITA and cannot see all the way in there to verify cleanliness. You can still get flow from ports to sides even if partially clogged and then gets clogged again down the road. If you have a bore scope, that helps quite a bit but a different intake can be had fairly cheap and should surface it if you do. IMO, that is. Yes, during disassembly, pay attention to all you make room with and replace as needed. Again, do it once. Also, replace the damn EGR valve and the MAF with quality replacements..... https://www.rockauto.com/en/moreinfo.php?pk=1112801&cc=1305076&pt=4968&jsn=893 and https://www.rockauto.com/en/moreinfo.php?pk=1988150&cc=1305076&pt=5128&jsn=909

 

[OilBurner2003]

Want to do it once? Pull intake and clean as best as can but sometimes the aggravation is a PITA and cannot see all the way in there to verify cleanliness. You can still get flow from ports to sides even if partially clogged and then gets clogged again down the road. If you have a bore scope, that helps quite a bit but a different intake can be had fairly cheap and should surface it if you do. IMO, that is. Yes, during disassembly, pay attention to all you make room with and replace as needed. Again, do it once. Also, replace the damn EGR valve and the MAF with quality replacements..... https://www.rockauto.com/en/moreinfo.php?pk=1112801&cc=1305076&pt=4968&jsn=893 and https://www.rockauto.com/en/moreinfo.php?pk=1988150&cc=1305076&pt=5128&jsn=909

Looks like it can’t hurt, MAF was already replaced luckily. Might do this soon if all else fails. Thank you for the links and the info sir!