George_Jetson

So what is your question? Do you want to know what the readiness monitors are? You have already stated the two most common reasons that they are not set.

Good advice, but I would also add to check the positive cables, including the wires to the alternator.

Since the car is just dies with not warning, it would be a safe bet to rule out fuel starvation. Assuming that, I would recommend a little bit of shotgunning (keeping in mind a buget of course). First I would swap out the EFI relay, you could check to see of the A/F heater relay is the same part number. If it is, I would just swap the two. The logic behind this is if the EFI relay was dropping out, intermintently, the engine would die as if the key was turned off. The car will run with bad relay for the a/f heaters, but it would set a code. I would also suggest closely checking the wiring harness to the crankshaft position sensor, and the camshaft position sensor. Paying very close attention to the crankshaft. If you do not find anything wrong, you may want to consider replacing the crakshaft sensor, (now to save money, I would recommend purchasing at a Toyota dealer, you want OEM quality, but there is no point in paying the Lexus markup). I would not recommend a aftermarket crankshaft sensor. Of course this assumes that you have already checked for loose wires under the hood, the battery terminals are clean/free of corosion. Most people do not realize how much affect a little bit of resistance can affect a circuit. If you consider OHM'S law, 1 ohm x 1 amp = 1 volt drop, so in a circuit that pulls 10 amps, just 1 ohm resistance can drop 10 volts, which leaves almost no voltage to run the circuit. Also that you have tried wiggling the key, and "light taps" ie read as hit, but do not go medievel ont he dash, near the key. You want to check for loose connections.

You could purchase a USB scanner, you can find them on ebay for around $30. When you car stalls, does it sputter or any other indication? Or does it shut off as if the key was turned off?

If you have a DVM that can measure DC current, you can disconnect the neg terminal of the battery and put the DVM inline with the battery. Measure the current draw with everything turned off. Normally a car will have app 20 to 60 ma draw (which is normal) anything more is cause for concern. If there is significanly larger draw, start removing fuses, one at a time, till you find the circuit with the excessive draw. If the draw is not excessive, have them check the charging system

I would suggest that you try having a friend turn the key on (but do not start the car), and depress the throttle. See if that gets it to move. I have not yet cleaned one of these yet, but have read a little about them. If this does not work let me know. I will post the question on IATN forums, I am sure they could get the answer. As far as cleaning, you are correct that using a wire brush is not a good idea. Get a can of carb cleaner and spray it, some Qtips or a clean rag should be all that you need. The deposits normally come off very quickly.

the fuel filters on our car are a lifetime part and almost NEVER require replacing unless your doing major mods Yes, but that does not preclude the possibility of a bad tank of gas. This car has relitively low mileage, I would not expect to see these type of error codes at this mileage.

Ok I have had a chance to check my manuals, those codes are not for the heater circuit. Start by looking for leaks in the air intake. Look for split hoses (especially to the pvc). Then check fuel pressure. If you do not have a gauge to check fuel pressure, I would suggest changing the fuel filter. In case you are not aware of this, you car has the fuel filter located inside the fuel tank. If you remove the rear seat, you will see a acess cover that allows you to pull out the entire pump, fuel level sender, and filter assembly.

I do not have access to my manuals (I'm at work now), but at this time I would suggest checking the fuse for the O2 heaters. Most cars use 1 fuse for the O2 sensors, if that fuse is blown, you would get a circuit failure and slow response. I will look up the codes later and give you some more details then.

There are several different codes for the O2 sensors, you need to find out what specific code you have because the procedure for troubleshooting is dependant on the specific code.

read this thread steviej Shortly after the previous tread, I read a tread on IATN (international auto tech network), where professional tech post for help from other pros. It was for this same problem on a Nissan, and the conclusion of the tread was that cleaning the throttle blade was the fix. Now as previously mentioned here, the car will learn the new positons in time, but as you can imagine for a professional mechanic this is not a option. They cannot return a car, and tell the customer to drive it until it stops stalling at lights. By having a clean throttle body, the base airflow is closer to what it was from the factory. Which make it easier for the ECM to re-learn the idle setting. Also keep in mind that forcing the ECM to learn from a corrupt baseline can cause other issues. I personnelly have not worked on any of these electronic throttle bodies, but I do have my ASE L1 cert, and the theory is sound. You would be hard pressed to find a professional mechanic that would disagree with the idea that the throttle body needs to be cleaned.

It is OBDII, so the same procedure as the 95 up. Perhaps the parts store was confused. OBDII had just started coming out in 94, most cars were still OBDI.

Harbor Freight sells a cheap set, very marginal quality, but it does work. I always recomend wearing safety glasses when working around compressed gasses. Better safe than sorry.

Unless you have opened your system, there is a very low probability that there is air in it. When you hooked up the gauge set, what were the high/low sides pressures? Make sure to have the engine running at a fast idle before checking, 1200rpm or so. I would suspect that you have a bad connection, bad switch, or the climate control itself is hosed. With the last possibility, I think that looking at the blower issuse should be put on hold for the moment. Focus on pressure switch issue.

I would recomend trying to isolate the leak first. You have a low mileage engine, and it is a little odd that it is leaking already. I would suggest purchasing a can of brake cleaner and spraying the bottom of the engine. The cleaner will remove the oil, and dry the area out. You will then be able to see where the oil is coming from. It may just be something as simple as the oil drain plug.

93 came from the factory with R12, so the first thing you need to identify if you car has been converted or not. You should check the fittings at the service ports and see if they are screw on, or quick disconnect ( both r12 and r134 dust caps screw on, so you need to remove the caps and then check the fitting ). If it is R12, it would be cheaper to have a professional recharge your system, because without a EPA 609 cert, no store will sell you R12. There are serveral substitues for R12, but none are designed to be mixed with R12 (besides the fact that it is against federal law). If you do mix R12 with a substitue there is no way to predict what the results will be, other than the fact that it would most likely be bad (or worse).

Don't forget the PCV valve, and the valve cover gromet that the pcv fits into.

How many kilometers do you have on the car. if you have more that 130km or so, I would recomend replacing both bank 1 and 2 sensor #1. They are consumable, with a finite lifespan. Of course if you have not already checked all vac hoses, it would be a good idea to check for split, cracked hoses first.

bank 1 is next to the firewall. You may want to clean the MAF sensor first, there are several people that state that this is a symptom of a Maf that needs cleaning (although why it does not set a code for both banks, I do not know). Anyway, it is much cheaper and could possibly fix the problem.

Are you looking for a key for the 93 LS 400 in your profile? I know that the 93 ES is not programable, on the back of the key is a FCC ID HYQ---- number (or something very similar) this is the transponder code, you will need a replacement key with this code. Otherwise there is a company, (which I do not remember the name), that sells a replacement chip that goes into the Remote reciever, and new keys. I would suggest a search because I am sure that they are cheaper than the Lexus alternative.

One other question, how many miles do you have on the car? Your car is OBDI which doesn't have O2 sensor heaters or some of the other checks that OBDII has. Was there any coolant lose before the rebuilt the heads? If so it would be easy to see one of the O2 sensors being contaminated (they are sensitive to contamination). The last thing to check would be the MAF, these years use a lo-tech (but much more adj, for the tuner) vane sensor. You need to use carb cleaner to clean out the build up in the sensor, and make sure that the vane moves freely, with no sticking at all.

Yes they are labled as you can see. I cannot explain why they do that, but I can assure you that my car is running fine without them. When your bf pulled the relays, were they from the positions that are blank? Or did he just pull the relays that were installed in the other positions?

I was a little confused, When you said that the shop wanted to rebuild the heads, and replace the gasket I assumed that they had not done that yet. So the next step would be checking the hoses, and then replacing the O2 sensors. I would strongly recomend replacing both sensors at the same time.

That is some 1/4 for 40 miles is real poor mileage. Are you sure the smoke is not black? Can you smell any gas when you stand behind the car? If you had a code for the O2 sensor, I would recomend replacing it, while you are at it, I would strongly suggest replacing the right hand O2 sensor also. You also want to check the vac hoses for splits,, MAKE SURE to closely inspect the vac hose to the fuel pressure regulator. When the engine vac is low, the fuel pressure regulator increases the fuel pressure so that more fuel will be injected (low vac, hard accleration). The other most likely possibility is the water temp sensor. When the engine is cold, the ECM runs the car rich. Does the temp gauge read app in the middle of the range? If it reads cold, then you need to fix that. If it reads in the normal range you could still have a sensor problem, because the ECM uses a separate sensor to determine the engine temp. As far was the head gaskets, are you loosing any coolant? How does the oil look? I am a little skeptical that the gaskets are a problem. If you had a blown gasket it would not run well for a while, then bad, and back to well. It would be bad, then worse.

I cannot locate the adapter to download the pictures, but I verified that the three relays are empty on my car.