gsfan

this has happened to me about three times already on the same tank of gas. I would stop at a red light, then my rpm would dip all the way down to 400 rpm's, causing the car to vibrate. My theory is that i got a bad batch of gas (Arco), or maybe a tune-up is needed soon? I was wondering if anybody here has experienced the same problem i have. BTW the car has 74k miles.

rominl

iTrader: (4)

not sure if it's gas though, i think it's just the design by itself. if you turn on the ac then you are fine

TLW

search Low idle

and be prepared

LB Lex

This reminds me. On Saturday I bought a new TPS sensor because my idle was a little eratic and brought it to a certified Lexus tech in Gardena (MT Auto). He checked the old one and confirmed it was not functioning properly, so he installed the new TPS. After installing it, the Check Engine, VSC, and ABS lights went on and the engine went into limp mode. I have never had these lights on nor did my engine ever go into limp mode. He checked the code and it showed that the other TPS was bad (yes, there are two: one on the driver's side ($70) and one on the passenger side that's attached to the throttle cable ($250-300, and yes, the parts book calls it a TPS). The TPS on the driver's side tells the ECU how wide the throttle is open. The TPS on the passenger's side electronically opens the throttle and also sends a signal to the ECU. He replaced it with a new one then checked the codes. It still said the same thing was the problem.

So he proceded to check the wiring just in case a mouse or rat chewed on it. In fact, several months ago I saw a dead rat in my garage. And a few months after I saw a half eaten candybar on top of my intake manifold. He told me rats and mice love making nests in the Lexus V8 under the intake manifold in the "V" of the engine. If you take a flashlight you can see there is a lot of room under there for something to squeeze in. Well, after doing some checks the wiring was good.

The guy thought that maybe it was the throttle body that was bad. Fortunately, he just happened to have a new throttle body assembly with all new sensors, so he installed it. The problem was solved, but I still had the low idle problem. So he checked and checked for a couple more hours and found no codes and nothing wrong with the car. The only thing we could think of was the computer. I asked him about it and he said Lexus has new "upgraded" computers. Then I asked him how much. Around $1,500-1,600. I said no way, I'd rather keep my A/C on all the time. I could only speculate that Lexus knows of the problem but does not want to spend all the money replacing the computers. BTW, my car is completely stock.

So in the end, he ended up eating the cost of the throttle body and sensors because my car ended up being worse than it was when I brought it in. I feel bad for the guy, he was really nice and spent the whole day with my car. I am definitely going back to him whenever I need repairs or maintenance done on my car.

To answer your question, just keep the A/C on and you won't have a problem with the low idle.

chuckb

how many miles? maybe your MAF.

house66

Hi,
My 2001 is in the dealership now for the same issue, it is a 2001 CPO car. I did all the research on this issue from all the other posts before I took it in and spoke to my service writer about this situation. I got a call back yesterday and my service writer advises that they are going to clean the throttle body and change the motor mounts, he mentioned that they had spoken to Lexus Corporate and they had suggested this as a fix. I will let you know how it goes, should have the car back today or tomorrow.

Cheers,

Lvangundy

I go there often..Tinh is a really knowledgeable guy. Very nice too as you said.

Have you tried changing your air filter or checking the intake tube? I took my air filter out for a few days to see how the ECU would react, and within two days the car was stutering and had a low idle when stopping.

jquest2

any CEL issues?