Redeemed68

YES!!! I had 2 codes, one for the V V T and the A/F sensor. I looked up my symptoms, replaced the actuators, cleaned and remove throttle body, IACV...runs great, increased fuel consumption and have gone over 500 miles without A/F sensor returning.
I still have some slow to shift or hard shifting issues while cold...that is probably another thread

babydoll02

I wanted to know, since I've changed every sensor including MAF, and just had the 1133 code off on me again.. do you think maybe cleaning the throttle body would stop this for me??

sf46

What is the IACV? How do I clean them and the throttle body as described? Is there a thread that describes this for a 1999 RX300?

carguy07

https://www.clublexus.com/forums/rx-...-write-up.html

Whallmark

I had my air fuel ratio sensor for bank 1 changed and I still got a p1133 code. Could the new Sensor be fault? please help!

carguy07

Was it an OE or Denso sensor or aftermarket?

Whallmark

it was a denso and it was changed a few days after christmas.

carguy07

Assuming they cleared the code and it was off for a little while? No other codes?

Whallmark

well the codes were a lean code and random misfires in the 1,3 and 5 cylinders. and after he cleared them.
I also changed the spark plugs. wiring harness, and coils

RandyRX300

Hi, Newbie here. I have a 1999 RX300 and also have that same code P1133. I have the check engine light on, difficulty with the shift to OD (thought maybe it was a VVT-i and Tranny communication issue) and lastly and most concerning, when I start the car when cold, I notice what looks like a little smoke coming out of the tailpipe. Can't notice it while driving. Car has 175K and has otherwise performed well, except for a slight loss in MPG. No noticeable use of oil. Any thoughts?

salimshah

Welcome to ClubLexus.

So what have you done to fix P1133?

Can you describe the color of the smoke?

Salim

RandyRX300

I have not done anything yet. Came here as soon as I got the code. I will take it to a shop and not try to do the A/F sensor myself. I am capable, but lack the tools and of course the time.
As for the smoke, I start it in a public garage with bad lighting, so hard to tell the color. I will look closer. It definitely is not vapor or condensate. I suspect it is blueish (bad news) or brownish which could be related to the A/F sensor. I want my mechanic to replace the A/F sensor and take a look at the source of the oil leak and give me an estimate. If the repairs are beyond the value of the RX, I'll likely trade it in on a newer vehicle, likely another RX.

salimshah

When you get the code, the problem is the value read by the on-board-computer is out of normal range. Depending on the age/milage the sensor can be bad, but there maybe other reasons too. The most cost-effective solution is to change the sensor. If further confirmation is desired, at times swapping out with the good side can be tried too.

We have a DIY that covers the change of sensor. Some of the tools can be loaned.

For burning oil, you have to investigate further. Compression check Leak down test, plug examination, catch-can on the pcv line can help.

Salim

RandyRX300

Thank you very much for the assistance. I had one of the "DOH" Homer Simpson moments right after I posted. A few weeks ago someone at work was touting the wonders of adding Marvel Mystery Oil to the gas tank and claimed that it increased mileage, quieted noises and preserves and protects engine parts. Well, guess what....we added some to my tank. Lo and behold, my check engine light came on, the A/F sensor is likely bad and there is blue smoke coming out of my tailpipe.
"DOH"!

I am going to take the car to the shop on Monday and have them replace the A/F sensor just because and also check the can on the PCV line. I hope they find a simple fix for the oil leak and if so, I will happily be back on the road with a sound vehicle.

I'll probably ask them to pull a plug and look at it too.

salimshah

I would suggest wait and run through couple of gas tanks of fills.

The additives can throw the combustion off.

Salim