curiousB

Hi Mike. You've been battling this for a while. At some point with 300k miles does it really matter? Not trying to sound flip but lets say it is the valve seat. Are you going to pull and head and do a valve regrind on a 300k car/engine? Why not live with as is until it's time to pass the car onto its next life? It doesn't sound like it is hurting you much other than a nuisance indicator while the car warms up on cold days? If the engine dies you can buy a used head from a wrecker or a whole new engine if you are really motivated. Other time for a newer LS.

Sounds like an urban myth....

Rule out ignition issues before touching the CATS. They are often cited as the problem but seldom are. Ignition on the other hand is a frequent problem. Go with the odds and sort out ignition first. Lots of posts on this site with procedures to follow to narrow it down.

Sticky/dirty IACV and/or vacuum leak. A vacuum leak is most noticeable when it is a large proportion of the air ingested by the engine (i.e. at idle). This is unmetered air by the MAF so the EFI gets confused and tries to correct a lean condition. At higher throttle the leak becomes negligible in proportion to the metered air so goes unnoticed. Maybe a cracked hose or your mechanic pulled a hose and connected it back incorrectly? IACV also very common complaint. If you clean TB you should really do this as well.

I had P0430 problem last summer. After changing a catalytic converter with no success I learned the problem was only leaks in the pipe. See below for more detail... http://us.lexusownersclub.com/forums/index.php?showtopic=70886&st=0

Its strange in IL if you have an OBDII car they don't even put a probe in your tailpipe anymore. They just look at ECU and ensure there are no emissions related codes. I guess they assume if the OBDII is happy that is as good as sticking a probe in.

Well just go into this eyes wide open. A 21 year old car is equivalent to a 107 year old human... Don't expect miracles. Also while these are are very reliable they are expensive when they need repair. If you are capable doing a lot of repair yourself you can save a bundle but if you are dependent on the dealer I would walk away. The broken odometer sounds suspicious. If a daily driver is mission critical for you I suggest getting something newer and maybe not a Lexus. $1000 doesn't buy much car these days. That's particularly true of a former luxury car.

Its not a catalytic converter. I'll bet you have exhaust leak after the catalytic converter either at the flange or underneath the Ypipe heat shield. Fix the leak first and save some $$$. http://us.lexusownersclub.com/forums/index.php?showtopic=70886#entry441548

Not sure this is the same as yours but perhaps gives some ideas http://www.planetsoarer.com/IAC/iac.htm

Its a bit strange because you don't need the serp belt nor the alternator to get the engine running. Maybe the car is just flooded and won't start because of it. An old trick I learned years ago was to remove the fuel pump fuse and crank the car a bit. This flushes out excess fuel in the cylinders and the car might actual catch for a bit and then die from fuel starvation. Replace fuse and then give it a go.

I had a low converter code (P0430) and all it turned out to be was a pipe leak after the primary converter and before the secondary one. I spend a few weeks figuring it out and swapped parts that were never a problem. Cost to fix in the end, a bit of welding.... see the whole saga in the thread below. I wouldn't rush out and swap parts prematurely. It would be better if you posted the ECU codes that caused the car to fail or was it a failure by exhaust probe measurement? http://us.lexusownersclub.com/forums/index.php?showtopic=70886&st=0&p=440638&hl=p0430&fromsearch=1entry440638

You don't need to drop the pan to do an electrical test. Just probe at the harness and save yourself a messy job.... Solenoids are just a coil of wire around a bobbin. Either they are shorted due to wires melted together (near zero ohms) or they are open circuit as the wire blew like a fuse (infinity or very high resistance reading). Solenoids can also jam mechanically but I would sort out the electrical story before dropping a pan.

Well maybe the heavy wire from the stud on the side of the alternator to the battery is corroded and limiting the current. The scenario is when alternator is lightly loaded no problem. Start turning on various loads and the alternator can't overcome the IR losses and you get the low reading. Where are you measuring this voltage and what point are you connecting negative? Could also be a poor ground from battery to chassis.

My repairs of LS430 since December 2003 111,900 miles 22 or so oil changes New passenger side door mirror. Stuck in forward open position. Rear axle height sensor replaced (AFS light stuck on) Timing belt and water pump replaced at 90K miles Currently on 3rd set of tires Leak in exhaust Y pipe after primary catalytic converters but before secondary converter. Replaced one parking sonar sensor in bumper. So I haven't had much go wrong in 8 years of owning the car. Hopefully I haven't just cursed myself. You'll have to decide if extended warranty is worth it for you. It really is repair insurance not warranty. The manufactuer isn't backing it as a new vehicle. It is after the fact insurance. These car are expensive to repair if they fail but they don't fail often. You feelin lucky? Read the fine print, there are a lot of exclusions in these warranties.

Here is the IACV. I like this idea from Rick Martin though. I'd go down that path first. It seems to match your symptoms well.

The knock sensor detects misfiring. The ECU then adjusts timing to compensate. Maybe semantics here but just wanted to be clear on cause and effect. I have heard of a guys cross wiring the knock sensors from bank 1 to bank2 and vice versa. Easier said than done as you need to somehow splice into the cable harnesses/connectors but that might be easier than disassembling the intake manifold to get to Knock sensor. Are you sure the engine mis fires? I was thinking a possible theory is everything is OK but the ECU is flagging a problem that doesn’t really exist (false negative) due to some subtle differences in how propane works vs petrol. Recall some of that Toyota dribble that described sensing cam shaft acceleration. Maybe propane doesn’t have the same acceleration as petrol (less energy) so the cam isn’t moving to where the ECU predicts it should. (This begs the question why wouldn’t you see it on more cylinders of course). Maybe you could swap the camshaft position sensors from bank 1 to bank 2 (and vice versa) to see if the offending cylinder moves with the sensor? Recall: To monitor misfires, the ECM uses both the Crankshaft Position (CKP) sensor and the Camshaft Position (CMP) sensor. The Crankshaft Position (CKP) sensor is used to measure variations in the crankshaft rotation speed. On the power stroke, the crankshaft accelerates. If the cylinder misfires, the crankshaft decelerates. The Camshaft Position (CMP) sensor is used to identify specific misfiring cylinders. Rough idle can be caused by dirty throttle body and sticking IACV. Maybe once the engine warms up a sticky IACV starts to move more freely. Doesn’t explain MIL/CEL light but maybe you have a couple things going on simultaneously that is confusing the matter.

Nice car. I envy your posh garage even more!! :whistles: Welcome to he forum. This is a great place to learn more about your car and share knowledge with fellow owners.

This isn't a catalytic converter issue. It would take weeks to plug a catalytic converter not four 25 mile trips...... You clearly have an ignition problem. What happens to engine when you just unplug the driver side coil? No change? What about the cap and rotor? Is the inside of the cap dirty and and creating a short path to ground? Clean it out with some alcohol and lint free cotton rag.

My only complaint is I wish they moved it around on the screen with each power cycle of the car. That lower right corner of the touch pad is going to wear out whereas a simple software change would move it around to spread out the wear.

Oh no he's started the launch sequence. Goodbye all..........

Tire pressure monitor reset button? Did you look in your manual?

I did the same thing recently on an emissions issue I had. Eventually you get tired of developing theories and feel like you have to try something even if it isn't relevant in the end. Closing off theories is helpful too. I know you changed the coilpack for the suspect cylinder to no avail. I wonder if your pulled the connector at the COP pack and spray bother ends with electronics contact cleaner. Plug it together and pull it apart 5-6 times (this is called wiping action and gets fresh metal to metal contact). Then trace wires back to ECU and do same thing at that connector. Maybe you just can a marginal driver wire to the COP and when things warm up it just moved into tighter contact. Just a guess, but costs nothing to give it a go.

You're not going to get any help with inputs like this.

Modern cars never actually stop using current from the battery. They drop to a very low power drain state called different things such as hibernation. The most common term is key off current. This can be measured with an ammeter in series with the battery. It should be less than 50mA but for sure less than 100mA. The with the car off and all lights and doors closed disconnect one side of battery (preferably the negative and run an ammeter in series. If you leave the hood open with this test check for a hood open switch and use a wire tie or something similar to spoof it into being closed just for the test period. Then wait 30-40 minutes to take a reading (cars don't instantly drop to low power state they gradually shed load items before they reach lowest power state). Thats it. If you see current of hundreds of milliamps or more it suggest maybe a trunk, glovebox, or other light is always on and draining battery. Failing that, a bad alternator with leaky stator diodes can act as a vampire current path and gradually drain a battery (although this is fairly rare). To see if it is the alternator disconnect +positive wire to alternator and re-do the key off current drain test.

bcuz she wont go steraight aneemore and u'll be on dah outside lookin in ceeing stars in yer iyes