dkakmcafee

I am receiving a code p0505 on a 2001 IS300. Can anyone tell me and show me exactly where this is located on the vehicle and provide a picture of the part? i am seeing 2 completely different parts when I Google it.

diagtime

IAC valve. what IAC valve. you have an electronically controlled throttle system. p0505 almost always means dirty throttle body. (or your dumb mechanic may just replace the whole thing). on an IS you will need to remove throttle body to clean it. Let me guess......your car also idles low with a/c on?

ravelink69

I got this issue too. are you saying there is not one on the car? I got the reading at Autozone and the troubleshooting tips say failed IAC valve and oreillys has it on sale for $200. but like you said above, when the a/c is on it sort of pulses like it is going to die....but not very severe.

if its like you say and just the throttle body, ill clean that this weekend.

diagtime

you will have to pull the throttle body off to clean it. be careful with the coolant line that goes to it that comes from the driver's side. make sure the clamp is tight when you put it back on. the coolant line coming from the passenger side (above ex manifold) can be left on if you're careful with it. make sure throttle motor is disconnected. never put your fingers in a throttle body that still has anything connected.

once off, cleaning the throttle body is simple. just put throttle body cleaner on a rag and clean the black stuff off. don't spray the cleaner in throttle body, just spray it on the rag. you don't need it to be obsessively clean.....just get the majority of the buildup off. If you did the job correctly, it will probably idle very high for a while until the computer relearns the position. and p0505 will not be bothering you anymore.

skitso1080

Just got that code last week, cleaned the throttle body and all is good.

dkakmcafee

I cleaned inside the throttle body and under the plate on top of the TB and have had no issues since.

ravelink69

hmmm i will check that out this weekend. I pulled the air intake tube off the throttle body but i was unable to reach the throttle so I will have to get at it from the other side. Hopefully this will fix my problem.

ravelink69

Well i went and cleaned the throttle body and its all nice and shiny. It was rather dirty, all black all over. Well after i cleaned it off, top and bottom, made sure there was no black in there AT ALL, the check engine light came back on after about 5 miles. Any other suggestions on what the next course of action would be? I couldnt find any obvious vacuum leaks like the code report suggested.

diagtime

Are you sure the code that came back was p0505. that code should only set if the idle speed drops to around 400-450 and stays there. I believe (not totally sure), that it's also two trip detection logic, which means the code won't set if only happens on one key cycle. Please make sure the code is still p0505.

ravelink69

Ill run back and get a code read tomorrow. The idle is a little higher than it was but it is still between the 2 tick marks that are below 1k

ravelink69

Looks like it is in fact a different a different code. Showing a p0570 which what the guy at oreillys is telling me is that is an O2 sensor, Bank 2 Sensor 2.

ravelink69

Actually, I think I wrote it down wrong. its p0057. So i guess my next questions would be does replacing the sensor fix this?

diagtime

p0057 is an oxygen sensor heater circuit code. replacing the sensor will take care of it 99% of the time. that particular sensor (bank 2 sensor 2) is the one that connects under the passenger carpet and goes under the car to exhaust pipe. it's the last one. I always recommend factory parts, especially oxygen sensors. these computers can be very sensitive to the brand and type of sensor. if the dealership part is out of budget, denso aftermarket sensors are by far your best bet. densoaftermarket.com should be denso aftermarket part 234-4517 but by all means double check me on everything.

ravelink69

Thank you for the help. I have located the sensor on my car and I found that autozone has the denso one for just under $100. Its manageable but itll have to wait until next paycheck. Thank you for pointing out which one it is.