craad

I have been driving my 2000 RX300 for about five years now and I've had a problem that has come and gone intermittently for 1-2 years now. There will be times where my car will not accelerate correctly at all. When I'm accelerating from a stand still or slow down to probably under 10 mph and re-accelerate, the car will accelerate to a very low speed for awhile and will not budge over a couple miles per hour until I just about floor it, which then it will get over the acceleration problem and rocket forward. While it is coasting at the very low speed when I am trying to accelerate, I can hear some clicking or knocking sounds which seem to come from under the hood or front dash. This problem will occur once every few months and last for usually 2-4 days, then it will vanish. My CEL is constantly on even when this problem isn't occurring.

Last year, I ran the codes from the CEL and I got the P0325 and P0330 codes which correspond to the knock sensors being faulty. After going through the DIY thread posted on how to swap these out, I decided to try my hand at it. I ordered the OEM knock sensors to do the replacement, and when I had everything taken apart under my hood, I came to find out that I had the wrong sensors due to the fact that Lexus apparently switched up the knock sensors mid-production of the 2000 RX300 and it is basically a gamble to figure out which one you have. Pressed on time and the fact that I needed to use my car, I kept the same faulty knock sensors in and I haven't had a chance to get back at it and replace them with the correct part.

Anyways, the issue of the slow acceleration and knocking sounds coming from the car came back again last week and it's getting to be very frustrating and dangerous in situations where I need to pull out and merge into traffic. I ran and got my codes checked again and these are the results:

P0125 - Insufficient coolant temperature for closed loop control
P0325 - Knock sensor #1
P0330 - Knock sensor #2
P1130
P1135
P1150
P1155
P1135
P1155

The last six codes came back with no description and for some reason P1135 and P1155 came up twice.

So, knowing all this, would it seem to be the knock sensor causing the acceleration problems? I haven't encountered other people on the forums facing the same kind of acceleration problems that I am experiencing. I haven't been able to shift into OD since the start of all this and I'm currently averaging around 13 mpg, which I would like to boost. I apologize if I was a little all over the place with my description and I can elaborate on whatever it is you need. Any suggestions on where to start and what exactly might be the problem is welcomed.

Thanks.

timmui

I wince at the thought of allowing an engine related CEL code to go unattended to for a year.

As for the codes, some of them are pretty common in the forum, so you might want to do a quick search.
P1130 and P1150 are your A/F ratio sensors that are commonly called (incorrectly) O2 sensors. I'm certain that the ones with similar numerical code but end in 5 are related. These sensors are just outside the engine on both banks.

Regardless, if you can't get the vehicle in OD, then it is probably in limp mode.

timmui

Speaking of quick searches... Seeing that I am seeing multiple threads on this, here is a link:

https://www.clublexus.com/forums/rx-...5-codes-3.html

craad

I have searched the codes and seen what they have been related to. The issue that I haven't seen as much or described the same way that I am experiencing is the noises coming from the engine when the acceleration problem occurs. Being in grad school and interning at the same time, I don't have the luxury of time to work on it myself as all my tools are not with me, nor the money as I have seen some of these repairs range from ~$1000-$1300. Trust me, I do not like one bit that the CEL has been on for this long. I just want to get some more information on these issues. Has anyone else heard of or experienced the clicking/knocking noise come from the engine during power loss? Is there any reason why two of the codes came up twice? Would one venture a guess that the A/F sensor is causing this problem or the knock sensor and is there a relation between the two? I really do appreciate any response, especially a link to another forum which maybe I haven't seen.

Thanks.

timmui

I will put my explanation more bluntly for you: You are driving in LIMP MODE and need to replace both A/F sensors to resolve these new codes. If you do the repair yourself, it costs you time plus two A/F senors. Around $300. If you don't have the time, the tools or the money, I don't know what asking in the forum will do to help you.

Please excuse my bluntness, as I tried to say it nicely first.

carguy07

I would agree with timmui. You probably need to replace both A/F sensors, they are $91.50 on Amazon right now (as cheap as you will find them)
Pay a mom and pop shop $100 to install them both and you will very likely be in good shape. I would do those first before screwing with the knock sensors.

Driving around in limp mode will give you all kinds of sounds and grief. The car is barely running, locked out of O/D and puking fuel our the exhaust.

salimshah

With so many codes, start by clearing them and read the codes on the first on-set of CEL.

CEL light needs attention. Some emission issues can affect your cat.

Regarding knock sensor .. if you had read the posted DIY, you will find instructions about taking your vin to the dealer.

Salim