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With it plugged in it runs horribly and if you touch gas it dies. with it unplugged it runs fine besides only revs to 3k .
If you're running stock engine management, then you need the MAF plugged in. That is an extremely vital sensor and you will never rev past 3k or have a properly running car without that sensor.

We need to back up here. You initially had an fault thrown for the Throttle Control Motor, has this code come back or do you still have a CEL? The TCM is responsible to properly adjust the butterfly electronically at idle and up to about 70% throttle. Now that your throttle position sensor is set for the correct voltage, and providing you followed my instructions perfectly, i would rescan for any new or pending codes. What i bet is happening is that your TCM is not adjusting the butterfly, possibly due to a bad clutch within that unit(which was also your original code). One thing that is for certain, the MAF needs to be functioning and always plugged in. Once you've done that, see if the CEL is on and rescan for any new or existing DTC's.
 

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Codes came back only as maf and iat sensors unplugged and plugged in and reset car cel light ie still on along with flashing trac light
 

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Well i would keep your MAF plugged in because obviously the car will not run without it. I'm very surprised you did not pull any other codes once the MAG was reconnected, especially with a CEL light. I wonder if your scanner really isn't picking up the stored code(s) or if you have poor spark to the plugs. How does the car run at WOT once it gets going?
 

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Hey guys,

I've had a CEL on for some time now and replaced an O2 sensor, which temporarily fixed the problem. Today I got it scanned at Autozone and it threw a P0420 code. So I saw on the forum that there are a few ways to check whats wrong (O2, leaks in the exhaust, cats) for this code.

But the guys at Autozone actually brought up the part (catalytic converter) for me and this is the model: Walker/Catalytic Converter (54666) | AutoZone.com

So my main question is, would this actually work for an IS? Rather then spending a crazy amount at a dealership I was wondering if this would be an affordable fix.

A mechanic told me that aftermarket parts such as these would not work and should not be used. But I have a feeling he is trying to rip me off.
 

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Im gonna try the tcm or parts store brought up idle control valve as same thing but its expensive anyone have an extra one for sale ebay is more expensive than the parts stores
 

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Hey guys,

I've had a CEL on for some time now and replaced an O2 sensor, which temporarily fixed the problem. Today I got it scanned at Autozone and it threw a P0420 code. So I saw on the forum that there are a few ways to check whats wrong (O2, leaks in the exhaust, cats) for this code.

But the guys at Autozone actually brought up the part (catalytic converter) for me and this is the model: Walker/Catalytic Converter (54666) | AutoZone.com

So my main question is, would this actually work for an IS? Rather then spending a crazy amount at a dealership I was wondering if this would be an affordable fix.

A mechanic told me that aftermarket parts such as these would not work and should not be used. But I have a feeling he is trying to rip me off.
I would always check for exhaust leaks and change the OEM denso oxygen sensor. You can get an exact for around $100 or Denso universal and splice in for half that. Do NOT buy a cat or exhaust part unless you are sure that is the problem. There are 3 tests i can think of.(IR temp gun, vacuum, smog)

Im gonna try the tcm or parts store brought up idle control valve as same thing but its expensive anyone have an extra one for sale ebay is more expensive than the parts stores
Yea, if you're are throwing throttle control motor faults or the related clutch, change it. There is no idle air control valve on this car, just the TCM. The MAF needs to be working and plugged in under stock engine management for sure. A scanner can tell us more such as realtime data and codes.
 

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only problem right now is getting money to buy the thing how exactly does it come off to i read somewhere that the throttle body has to come off is that true
 

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only problem right now is getting money to buy the thing how exactly does it come off to i read somewhere that the throttle body has to come off is that true
It's actually pretty easy. Follow the spark plug diy to disassemble the throttle body so you can clean it thoroughly and both sides of the butterfly. You do not have to remove the two coolant lines and i suggest not doing so unless you bleed the system. Remember to clean under the plate on top held on by two philips screws(which can be done anytime). Idle air passes through there and I'm betting yours is pretty dirty. All you need is some metric sockets and some extensions, a clean rag, and some carb/TB cleaner for the job. It make your engine breath hella better! It helped my idle issue and only took an hour or two and that was with removing it. Also remember NOT to move or soak the 3 electronic parts, the throttle position sensor, controller motor, and apps. Don't even loosen the mounting screws unless you plan on using a voltmeter to reset them. Hope this helps, gl.

http://my.is/forums/f221/spark-plug-replacement-diy-lots-pics-printable-pdf-attached-254217/
 

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p0300,p0301,p0302,p0303 2002 is300 idles bad and runs bad but as soon as you crank it its fine then after 30 seconds or so it starts running bad any help would be great as to why only bank 1 is misfiring
 

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p0300,p0301,p0302,p0303 2002 is300 idles bad and runs bad but as soon as you crank it its fine then after 30 seconds or so it starts running bad any help would be great as to why only bank 1 is misfiring
Bank 1 oxygen sensor would be suspect. Compare voltage outputs with the other bank. Doesn't wound like ignition problems but verify the spark plug valley isn't filled with oil.
 

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p0420 p0422 p0400
any help would be great
P0440 (evap emission control sys malfunction). Troubled areas:
Hose cracked, holed, damage or loose seal.
Fuel tank cap not installed properly, cracked or damage.
Vac hose cracked, holed, blocked, damage or disconnected.
Fuel tank cracked, holed or damage.
Charcoal canister cracked, holed or damage.
Open or short in vapor pressure sensor circuit.
Vapor pressure sensor.
Fuel tank over fill check valve cranked or damage.
ECM

P0422 means Main Catalyst Efficiency Below Threshold (Bank 1)
Means that...
Bad or non-functional catalytic converter
Engine operating out of optimal air:fuel ratio
-So this could mean the cat isn't doing it's job properly or the car needs a tune up. Is all maintenance up to date?

P0420 means bank 1 catalytic convertor efficiency is below threshhold.

Seeing that you have both P0422 and P0420, i would think you bank 1 cat needs checked out to see if it's doing it's job properly(if you still have cats, if you don't, you'll need a sim/delete to remove and keep cat codes from coming up. Otherwise, I would have your cat checked for leaks, leaks in the exhaust system, and the cat itself checked to see if it is working right(smog check, temperature check, and/or vacuum test on the cat).
 

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DTC No. - P0505
DTC Detecting Condition Trouble Area - Idle speed continues to vary greatly from target speed

Trouble Area - Air induction system, Electric throttle control system
Check air induction system. Repair or replace. Check electric throttle control system, Clean throttle body, Inspect Throttle Valve, Inspect Throttle Body Operation, Inspect Throttle Control Motor, Inspect Throttle Position Sensor,Inspect Accelerator Pedal Position Sensor. Replace defective parts

There is no idle air control valve, no idle speed controller, or EGR system. With VVTi valve overlap can be controlled to create an EGR effect,
eliminating the need for an EGR valve. The entire throttle is electronically controlled, and idle speed controlled through the ETCS. What I would do is clean your throttle body and butterfly using carb/TB cleaner. on top of the TB is a 1"x3"(roughly)
rectangular plate held on by two philips screws. You take the cover off and there are a bunch of tiny holes in which your idle air passes through when the butterfly is closed. When I cleaned those holes out I noticed better idle. Definitely worth cleaning and may help with your code. Takes all of about 5 minutes to clean. I can tell you that I've responded to members threads that directly related to DTC P0505, and the simple cleaning as mentioned above took care of the problem with no more code. I would try this first, clear the code, and see if it returns.
from my previous..
 

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Here is a diagram of how it's layed out:

http://i6.photobucket.com/albums/y219/Digger08/Evapsystem.gif?t=1238372098

possible causes of P0442:
-fuel tank cap incorrectly installed
-fuel tank cap cracked or damaged
-vacuum hose cracked, blocked, damaged, disconnected(hose 1,2,4,5,6,7,8,10,11-see image above for hose #)
-fuel tank cracked, holed, or damaged
-chacoal canister cracked, holed, or damaged
-open or short in vapor pressure sensor circuit
-vapor pressure sensor
-fuel tank overfill valve cracked or damaged
-ECM

I see you said you just put your intake back to stock. I would verify the canister closed VSV is connected, which is located right by the stock air box(to the right as you look at the box). The bottom of the valve is supposed to be connected to the bottom of the air box with a short piece of tubing, and the connection(tubing) on the side of the valve goes back to the charcoal canister. I would verify that and check the gas cap to rule out the easiest. hope this helps.
Just changed the gas cap and reset. Code came back. Will run this list of possibles. Great post!!
 

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P0430 and P0051

Just recently put on a new cat-back exhaust system muffler, and a megan racing down pipe (y-pipe). I got the code P0141 and replaced bank 1 sensor 2. Drove for a hundred miles and light came back on, code P0051. I replaced Bank 2 sensor 1 and cleared code. Drove another hundred miles and it came back on again! code P0430. Catalyst Efficiency below threshold bank 2. Does this have anything to do with there being no cat on my new down pipe? or does it mean the cats on my stock headers are junk? Any help for the newbie? lol
 

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Cel and trac flashing

I own 2001 is300 and the cel is on as well as the trac off is flashing. I was able to get codes from a failed smog. P0440, p1120, p1121. I have looked them up but don't know how to start fixing them. My car will drive fine for awhile but then it seems like I have to floor the pedal for the car to go any faster. Help on this would be great.
 
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