I keep getting check engine light code 12. The light was coming on after engine warm up and driving about 6 - 10+ miles. I checked EGR valve and found the diaphram leaking vacuum. Replaced the EGR valve. The code light now comes on after engine warm up and driving about 2 miles in other words the code light comes on sooner than before. I thought the EGR valve defective and replaced it. Same problem. Checked the EGR vacuum and it holds. I've checked the vacuum to the #16 hose and it checks zero at idle. Applying vacuum to the EGR causes rough idle. Battery voltage checks out at Black /Yellow wire pin at the main harness 4 pin connector at the control box as does the ground. When terminal B is grounded and voltage is connected to terminal A on the control sode, vacuum increases to hose #16. The control solenoid seems to be ok. I'm stumped and cannot get the engine check light to stay off. Any help out there? It sure would be appreciated. All I can figure is that the ECU mught be sending incorrect info or somehow the control solenoid is not working properly. Thanks,Bill

 

Well, hum, ahhh

 

Feeling kinda dumb .... It's a 1992 Accord EX. 2.2L

 

I have a very similar engine, and I know for sure that my engine is supposed to die when I apply vaccume to the EGR at idle... Yours only makes your engine run rough, correct?

This leads me to believe that you have insufficient flow through your EGR valve, but our OBD1 simply lists it as an EGR problem (code 12 is EGR correct?), not insufficient flow like a newer car would tell you...

If everything else is checking out and you still are getting a code for it, try cleaning the carbon out of your whole EGR system... I also just had a thought, have you checked out the EGR lift sensor? if its sending no signal, or the wrong signal to the ECU it will trip the light...

Let us know what you find!
sohc

 

or it will stall but most of the time it will want to stall and still run like crud.

 

Hmm, has the EGR system ever been manually cleaned out? A car that old (like mine) must have some miles, and is likely partially clogged up with carbon. Check out the FAQ for detailed instructions...

Another thought, check for any cracks or leaks in the vaccum lines to and from the EGR system, even if all the components are working fine, a leak will screw things up...
sohc

 

Thanks for the tips, I'll try cleaning the system and the check vacuum lines. I've tried cleaning the carbon but maybe not done enough. The engine runs well enough but idles rough when in gear and under load from the a/c. Before the light comes on after resetting it idles nicely @ about 650 rpm. Thanks again. I'll get back after I've tried these tips. Bill

 

Oh forgot, the engine is origial and I'm the original owner as well as the car driven mostly to school (work) by a beautiful school teacher (my wife) B4 we bought a new Pius this year. It has 210K miles, town and freeway to work.I'm just trying to get everything back in good working order. I know it still has lot of miles left for me. Thanks again, Bill

 

my old lady's car did this too. loo up egr on here and one of the threads has instructions on how to clean out all the carbon build up, in case you didnt know how too. remember to change brand of gas(shell, chevron, etc) every 3 fill ups or so. That will keep carbon build up from occurring, atleast less than usual. good luck

 

sounds like somthing is still wrong with the EGR system when you replaced the EGR valve did you get a brand new one and not a used one ? as if used one can still be bad also have you checked to see if theres vacuum to the EGR valve? and that the solenoid cuts off vacuum when it should? those are the only 2 things that will cause a code 12 as OBD1 doesn't care about flow as lone as the valve opens when it should and the values are correct.

 

I'll check the thread about cleaning carbon @ EGR ports. That should be useful. I did check the vacuum @ EGR and values to/from the control solenoid and they check out. At this point I'll try to go back to the carbon clean out and check the quality of the vacuum hoses, 210k can cause some wear & tear. Thanks Bill