EGR valve/tube and IAC valve questions
02-02-2013, 12:54 AM
#1
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Join Date: Feb 2003
Location: San Diego
Posts: 223
EGR valve/tube and IAC valve questions
In an effort to reduce my high NOx emissions, I removed and cleaned my EGR tube and IAC valve. Now I'm noticing after putting everything back and starting the engine that my idle is higher. Between 1.5k and 2k RPM, whereas before it was right around the normal 1k RPM. Maybe it'll go away over time, but anyone have an explanation? My air intake manifold (have a K&N cone filter in place of stock) seems to have increased its hissy noise, too. Or maybe I just didn't notice it before. Could all this just be because of the cleaned passageways?
Now on to the EGR valve. I decided while I was at it to see if I could do the typical EGR valve test - get my finger up under the valve and push up on the diaphragm. What I got confused about though is where exactly the diaphragm is. Is it all the way at the very bottom of the part or is it on the bottom of the wide saucer-shaped contraption on top of the part? I tried pushing up on these two locations both when the car was off and when it was on. Nothing budged. Either my EGR valve is stuck/clogged and needs to be replaced (or maybe just cleaned?) or I'm pushing up on the wrong spot. What I'm sure of though is that I'm not confusing the EGR valve for some other component. Any suggestions?
Now on to the EGR valve. I decided while I was at it to see if I could do the typical EGR valve test - get my finger up under the valve and push up on the diaphragm. What I got confused about though is where exactly the diaphragm is. Is it all the way at the very bottom of the part or is it on the bottom of the wide saucer-shaped contraption on top of the part? I tried pushing up on these two locations both when the car was off and when it was on. Nothing budged. Either my EGR valve is stuck/clogged and needs to be replaced (or maybe just cleaned?) or I'm pushing up on the wrong spot. What I'm sure of though is that I'm not confusing the EGR valve for some other component. Any suggestions?
02-08-2013, 10:54 PM
#3
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Join Date: Oct 2006
Location: los angeles, ca
Posts: 25
i have been having the same issues. had high NOx at smog and went ahead and did the whole cleaning bit. TB, IACV, UIM, ERG System, replaced the valve covers, cracked hose, pcv, all sorts of stuff. Anyway, after putting it all back together, got a P0400 code for EGR flow malfunction, took the EGR valve and ERGb Valve off and cleaned them again, got P0400 to go away after it all went back together, but then got P1105 and a high idle just like yours. Consulted the first section of the FSM in the EC section and found the vacuum diagram. I found one small vacuum hose was disconnected at the bottom right of the TB (nearest the firewall) got the back on, idle returned to normal and codes went away. first time in 10 years the CEL has stayed off! I'd say double check your vacuum connections
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shilov
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