gsrthomas

iTrader: (1)

Well I have a check engine light on. Starts just fine. Used to stall when cold but now I just have a CEL. CEL been on for around 10k miles. I cleaned the Idle Air Control Valve about 30k miles ago.

Since my car has 106k miles on it. I did a full tune up not to long ago (still have to change the spark plugs).

Should I just buy a new IACV? How much are they? I just want to be worry free of this IACV problem for another 100k miles or so.

Thanks for your input!

Lexmex

What is the CEL code you have?

tcheung87

CEL might not be related to IACV, you should get the code pulled like Lexmex said.

gsrthomas

iTrader: (1)

I checked the code a while ago and I believe it was the IACV. I will scan it again and see if it really is it. CEL has been going on/off for a year now. Apparently now its staying on. I will go to my dads shop tomorrow and check the scan the CEL.

gsrthomas

iTrader: (1)

I had a total of 6 codes. Some were duplicates.

They are:
P0440
P0441
P0446
P0500

Some are related to emmisions. Maybe I didnt have my gas cap tightened enough? I accidentally erased the codes before I can write down the definitions of the codes from the scanner.

Once the check engine light comes on again I will immediately check the codes. Think this is a more accurate way to determine what is wrong.

Does the IACV has its own fault code??

onepointon

just replacing the iac would be a waste of money.

i dont remember wht the p0500 is off the top of my head, but the 440, 441, and 446 are all evap codes. make sure your gas cap is tight. also, make sure you plugged in the air hose on the intake box from when you cleaned out the iac. you said you cleared the code, so if it doesnt come back on after checking those two things, your good to go. if not, it may require more diagnostics.

gsrthomas

iTrader: (1)

Yeah I cleared the codes. Been 3 days now and they haven't came back.

I replaced my Spark Plugs today. The 3 rear bank spark plugs were a pain to replace but not as bad as I antisipated. Now I'm officially done with my 100k tune up.

gsrthomas

iTrader: (1)

Well check engine light came on again. I checked it immediately this time.

Scanner says the following:

P0505 - Idle Control System Malfunction

My guess is the Idle Air Control Valve needs replacement/cleaning??

Can anyone confirm this for me. I dont want to clean/buy the part if I don't have too.

Lexmex

Could be the IACV itself, but a lot of times on other vehicles there is a small leak (perhaps a gasket issue), but I would at least try cleaning it first and then see if the code returns.

Raoul

My knee jerk response was just buy a new IAC valve because that's what I did with my Ford for around $65.

I just searched for a RX300 IAC and the best price I found was $207.

I must withdraw my intended recommendation and instead apply logic used for expensive Ford and BMW repairs.
If your Lexus is idling without issue and the dashboard light is telling you to replace the $207 IAC valve, place a 1 inch by .5 inch piece of black electrical tape over the offending light.

lexus114

Problem with that is,in my state the vehicle wont pass the emissions test with any codes in the system.(hence check engine light)

Raoul

I've heard that is true for some counties/cities in northern VA too.
It's not statewide down here...yet.

Until then, all I keep in my toolbox is duct tape, electrical tape, a hammer and a big hammer.

gsrthomas

iTrader: (1)

The engine runs fine. It just idles really high when warmed up, 1200-1300 RPM.

I cleaned the IACV instelf a while ago. 2-3 years?

I might just purchase this part and get it done with. I recently did a major tuneup so if I replace the IACV I should be good for another 100k miles.

bob2200

If it makes you feel any better, my mechanic up North works for a Lexus dealer and he told me that they replace, rather than clean, IACVs.

onepointon

FWIW: i never clean them either at my shop. i just replace them. i used to clean them back in the day, but they usually fail down the road and i get a customer comeback. at a dealership, you dont want to have them comeback unhappy. rather than sending someone out the door with a IAC that might fail again, you get them a new one. customer spends a little money, but their car is properly fixed.