Pablo1992

I have a 2001 Lexus Rx300 and it's been acting funny lately. I took it to Auto Zone so they could run their test on it and they said it was the coils that were misfiring and 4 cylinders were not firing right. I took it to a mechanic they referred me to and they called me today and said it was the computer and I had to get a new computer for it and take it to the Lexus dealership so they could program it. Could someone explain this to me, what is the computer and what exactly is wrong with it?

Also There's a noise near the steering wheel that's like a ticking. When the car is on cold all the way and defog and defrost are on it kind of runs but it sputters and shuts off and when I push on the gas it doesn't accelerate, I just have to keep my foot lightly on the gas. If the Heat is on all the way the car won't run it'll sputter and shut off automatically.

How much would the parts I need to get cost and what's wrong with it?

thomas1

We need the codes that you got at Autozone...The problem could be nothing more than bad coils, but without the codes we are clueless.

salimshah

I would only listen to Lexus mechanic when main ECU needs replacement.

Salim

code58

Salim told it like it is!

twojayzee

If the car is running, the likelyhood of needing a new ECU is about .001%
The stealerships cannot program the ECU to change anything. Post back with your PO codes and we'll see if we can help.

Pablo1992

I don't know what the codes are cuz my brother threw them away. Autozone pumped out about 13 different code with their little machine. I remember him saying these were the most important ones.

3 or 4 pistons were misfiring

another one was for the coils.

My dad looked at the engine and he said one of the spark plug wires was exposed.

Here are some respones from some other Lexus boards and yahoo answers people have told me if it could be any help. Thanks again,

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Don't know what's wrong with it the garage should of told you that. the computer basically tells the car what to do and when they put it in they have to reset it for the make/model car with the options you have in it. just like your home computer if something goes wrong and they have reboot it after doing work to it. as for other problem it might have something to do with the computer or another problem but until computer problem taken care of don't know. the computer cost can be several hundred dollars plus labor for replacement

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Dennis

I'd take it to the dealer. A computer is a hard call to make and it doesn't sound like a computer issue to me. A new computer has to be programmed to match the chip in the key. and to match all the components. The dealer at this point is your best and probably cheapest option. I have a regular customer with that same vehicle and I would farm this problem out to the dealer because they have better equipment to diagnose and will be cheaper in the long run. Since it will end up at the dealer for reprogramming anyway. It might just need to flash the computer with updates to fix it. This might not be a cheap fix no matter what so cutting out the middle man will be your best bet at this point.
5 hours ago

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If the car is running, the likelyhood of needing a new ECU is about .001%
The stealerships cannot program the ECU to change anything. Post back with your PO codes and we'll see if we can help.

hypervish

It sounds like one or more of your coils is bad, and the engine is misfiring.

If you can take it to AutoZone again, and get the codes read it will be helpful.

salimshah

It may be worthwhile to purchase a code reader.

If not ... disconnect battery for 20 mins or so. On the first onset of CEL drive to a location who can read the code(s) for you. When you have too many codes, it is important to figure out the first code(s).

Diagnosis must be done in a logical fashion.

Salim

amblyn

This might be way off but i had a bad air/fuel sensor throw about 13 codes after driving like that for a while. caused it to misfire in bank one. so like people have said reset the codes. then check first code pops up.

a mechanic told me when i brought issue to him that none of the codes except misfire codes matter figure out what causes misfire and thats your problem. well i wouldnt have figured out the misfire cause unless i investigated the original first code i had wich was bad airfuel sensor but we cant help you much with no codes. could be multiple things codes help pinpoint

code58

I again agree with Salim. Everyone who can read and is able to pass the driving test should own a code reader. They almost sell them in vending machines these days, they are so reasonable. And plenty of help on the "Net" with interpreting the codes. Knowledge is power, and when dealing with todays autos you need a lot of knowledge, (unless you have a VERY large bank account ) Always cancel the codes out after you have read 'em (and recorded them) and then see what shows up 1st when the light comes back on. That's going to give you a better idea of what the problem ACTUALLY is.

Debbs

Similar Question, please: I'm getting conflicting info from different mechanics. I have a 2001 Lexus RX300 with 250,000 + miles. My baby.

Engine warning light came on. Autozone code reader said to replace the knock sensor and harness. Code P0325. Done.

Engine light came back on a few days later. Mechanic said i needed a new battery and that could have thrown codes. Nice shiny new battery: Done.

Two days later engine warning light came back on. Returned to repair shop, mechanic said it may be the car's computer... He's going to check all the electrical again next weeek. But after that i probably need to go to Toyota dealership for a new computer and have everything reprogrammed....(i am nowhere near a Lexus dealership

i saw somewhere on here that if the car is running it's not likely the computer. It's running, but i can hear pinging when i step on the gas.

Old friend and mechanic way back home agrees it's not likely the computer.

Has anyone run into something like this before? Thanks!

LeX2K

I can take a guess and say your mechanic did not use Toyota knock sensors and other genuine Toyota parts. It's possible the ECU needs to have all the electrolytic capacitors replaced but an ECU with this type of failure tends to have more random codes not same/consistent ones.

salimshah

After ensuring the quality of replaced knock sensors and knock-sensor wires [the wires should be replaced], a good mechanic will look for actual knock going before assuming that knock sensors are giving out false signals.

Salim

Debbs

thank you

Debbs

Thank You, too. I'm gathering questions. i appreciate all the help