IACV Question
#1
IACV Question
Hey guys, so I chased down all my misfire woes and changed out the plugs, wires, and coil packs. Also changed out both pre-cat O2 sensors. The scanner is showing a p0150 and p0171 now. There's also a rough idle only in drive. The odd part is that the SES light isn't on, but the scanner is picking up the codes. I unhooked the IACV and ran it without it hooked up and it cleared up the rough idle and codes. Now it's just the throwing the IACV codes p1551 & p1514.
What does the IACV do exactly? And can I run it without the IACV? My state has no emissions test if its simply a smog thing.
Thanks
What does the IACV do exactly? And can I run it without the IACV? My state has no emissions test if its simply a smog thing.
Thanks
#2
Many codes are "multiple offenders" in that they must happen on two or sometime more drive cycles, before the engine light comes on. You are seeing a pending code.
IACV is a computer controlled vacuum leak that makes idle smooth. You need it connected. The IACV can be cleaned with carb cleaner.
IACV is a computer controlled vacuum leak that makes idle smooth. You need it connected. The IACV can be cleaned with carb cleaner.
#3
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#8
Join Date: Apr 2006
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If you had a better understanding of the idle control solenoid you might get it. With it unplugged the engine has no way of maintaing an idle because the IAC is the only way the engine gets air when your foot is off the gas.
As for the codes, if you have replaced the 2 front 02's, have you verifiey that the 02's are working per a scanner and did you clean all the oil out of the connection?
As for the codes, if you have replaced the 2 front 02's, have you verifiey that the 02's are working per a scanner and did you clean all the oil out of the connection?
#9
Thanks Mike, that's why I was asking what role the IAC played since it ran fine with it unplugged. I was trying to expand my knowledge on that subject.
I checked the O2 sensors with the scanner and bank 2, sensor 1 was reading 0. I swapped the two front sensors to see if the 0 reading followed. It followed, but the p0150 stayed along with a new p0154 code.
I believe I got a faulty O2 sensor from the auto parts store, so I'm swapping it today. I'll let ya'll know if that fixes the issue.
Also, I've cleaned the connections a few times to ensure there is nothing blocking signal.
Thanks
I checked the O2 sensors with the scanner and bank 2, sensor 1 was reading 0. I swapped the two front sensors to see if the 0 reading followed. It followed, but the p0150 stayed along with a new p0154 code.
I believe I got a faulty O2 sensor from the auto parts store, so I'm swapping it today. I'll let ya'll know if that fixes the issue.
Also, I've cleaned the connections a few times to ensure there is nothing blocking signal.
Thanks
#10
MtnRunnin,
Have you opened up the engine wire harness above engine on firewall to see if it got wet during pressure wash? This should be easy enough to do: un-clip it and un-tape it. Look carefully for bare or corroded wires. Also, you might want to check to see if water got in the harness through firewall, and followed to ECU connection up under glove box, causing corrosion ("fretting" in technician parlance.) Good luck!
Have you opened up the engine wire harness above engine on firewall to see if it got wet during pressure wash? This should be easy enough to do: un-clip it and un-tape it. Look carefully for bare or corroded wires. Also, you might want to check to see if water got in the harness through firewall, and followed to ECU connection up under glove box, causing corrosion ("fretting" in technician parlance.) Good luck!