So after a long and hard fought battle I finally got my ERG system to stop throwing cell codes at me. I thought I would give a little write up since lots of people have this issue and ask "How do i fix a code 12"

Background, 4th gen w/ H22a swap......

once the engine gets to operation temp and rpms are at crusing speed, bam, CEL 12......

so, first thing i did was check the EGR valve as they can get dirty and clogged..... i cleaned it and put it back on... no good....

next i replaced it with a known working one and still nothing.....

checked all the vaccume lines and with the engine running i made sure they had vaccume. There is a vaccume hose comming from the intake manifold to the Vaccume Control Unit, a vaccume hose connecting the VCU to the EGR control soleniod. , and then one from the EGR control soleniod to the EGR Valve. there was vaccume from the IM to the VCU, and vaccume comming into the EGR Valve.

i did a little suck test to make sure that i could open/close the EGR valve by sucking on the vaccume line and it worked fine.

I figured that maybe the Soleniod was sticking so i took it out and sprayed Lube/Cleaner into the 3 ports and shook it out......

plugged it back together and went to drive..... Car would choke out and die if i let off the gas..... Oh crap, what did i do.......

i had 2 vaccume lines reversed. As i was fixing that, i wondered if the Vaccume control unit was still good...... eh, ill check that if it does not work again....

went for another drive and threw the cel...... pissed was i.....

so, i take the Vaccume Control Unit out and notice that it has a small spring loaded part inside that was sticking due to this white powery stuff.... give it some hits with lube/cleaner and it started moving just fine.......

put everything back 2gether the right way and go for a drive.... no cel.....

drive 30 min to work today and no cel.... weeeeee

 

Nice. Good job on the tech stuff. Should come in handy to plenty of people.

 

anything to help the cause