Concerning the A/F sensors- yes, 2 exactly alike, on the front and rear exhaust manifolds. Original Toyota #89467-48011 (Denso). 48011 is replacement for 48010. You may find it under the Denso aftermarket as part#234-9009. You can find them from an online Lexus dealer for $150. ea. which is a very good price. I wouldn't use ANYTHING but OE Denso. I would still make certain you needed them before you replace them since they aren't cheap.

Sorry, YH, I guess I was researching while you were typing.

 

Agree on the Denso OE...many reports of aftermarket, especially Bosch, not working right in this application. Originally there were two different A/F sensors - identical business end but different wiring harness length. Looks like Denso did the smart thing and converged on one identical sensor for both banks.

 

Thanks everyone for all the information. Greatly appreciated. So, after driving through 2 tanks of gas, I decided to buy the 2 Denso A/F Sensors (300$ total) and have them put in (labor 110$). I also got my Transmission Fluid flushed (Toyoya IV ATF) replaced and oil changed (Mobil 1 - 5w30). All codes are now gone. So, I took Rex out for a test drive and noticed that it still runs a bit rough for the first little bit (6-10 minutes) and the transmission hangs at about 3000 RPM(I don't go any higher in the first few minutes of driving based on what I read on this forum) and the eventually runs back down to 1500-2000 range right after jumping into the next gear when I first start it up and drive. This seems to only happen when the Temp level is in the Cold region, things smoothen out a bit after about 15 minutes. Normal?

I can't help but notice that there is a whining sound that comes on when I go faster than about 45 MPH (almost sounds like when your ears are ringing or like that multi-coloured barcode channel when a TV Station is off air at 4 AM) - after some lurking on here, people seem to thing it may be a tranny issue. But, I just had my tranny rebuilt less than 1 year ago via Mister Transmission. Last of all, when driving on the highway I get this feeling that the car is about to slip or give out (Same feeling I got before one of the coils went out in the past). Talk about a hypochondriac After dropping close to 1000$ in total, just want to be sure I'm maintaining Rex in the best possible manner (yes, I also read the transmission preservation post - thanks LEXMEX)

Any thoughts?


-Y.H.

 

When the vehicle is cold, the transmission fluid needs time to warm up before it will shift up, so don't worry about that.

Not sure about the whine.

BTW, do you have an AWD or FWD (can't remember if I asked)?

 

Wow, LEXMEX, that was less than 5 mins. Incredible! Sounds good, I'll let my car idle for 13 minutes before driving it around (still pretty chilly outside). I have an AWD.

This weekend I'm going to clean the MAF Sensor as well.

 

Since you have AWD, have you done your transfer case and rear differential?

https://www.clublexus.com/forums/rx3...sfer-case.html

I plan to update this DIY once again in the not too distant future, this time using a hand pump you can get at any auto parts store.

 

Awesome! I totally forgot, I had my rear differential done about 2 weeks ago, but not my transfer case. Do you think that will make a difference (transfer case)?

Thanks so much again for all the help.

 

Yeah, it will. I noticed it especially between 2nd and 3rd gear after I cleaned out the first time (as shown in that thread).

 

Fantastic. Man, you really know your stuff. I'll get that done this weekend as well and report back with the results.

Y.H.

 

I`d say 5 minutes is plenty.Any more,and your just wasting gas.

 

So, I went to my mechanic and he insisted that he changed the transfer case oil while he did the front differential and the rear differential was done as well. He also checked and made sure that all levels were fine. I asked about cleaning the MAF Sensor and he didn't know how, but when I initially went to JL once this whole ordeal started, I remember they did a fuel system line cleaning - after calling JL they said they may or may not have cleaned the MAF Sensor.

More importantly, I still get the "chug-a-chug-a-chug" sensation when driving. Almost like something is about to blow. :S NO CEL is on, but it just feels like it's chugging/clunking along, despite 5-10 minutes of warming up in (-5 C temperature).

I'm on a placement in a rural area for most weeks and my biggest fear is getting stranded out in BFN. Of course, there's no Lexus dealership that I can take this to for an inspection. So basically, all I've got is you guys until I go back to the city after my placement. *fingers crossed*

Thanks in advance,

Y.H.

To be a bit more specific: While going 60 KM/H, the whole vehicle rocks back and forth as if it's trying to push itself forward, the steering wheel vibrates, the gas pedal feels like it has a pulse/ABS(and as though if I put anymore pressure down it will cause the vehicle to explode). The RPM doesn't jump by any means. After driving for about 3 minutes further down the road, things smoothened out considerably, although that clunking/chugging sensation can almost faintly be felt and heard.

 

Have you been able to see if any pending codes show up in the computer?

There might be an issue there with what you describe involving the IACV valve, https://www.clublexus.com/forums/rx3...-write-up.html

I know that recently I had some chugging on mine and had to clean it out, but that was more at idle and when I used to run my lower bullhorn intake (something I don't need at this altitude).

 

Thanks a bunch LEXMEX. I'm going to look into the pending codes when I get a chance (this Friday).

I had a chance to read over the post with the IACV and recall watching the guys at Mr. Lube follow similar instructions and showing me the dirt they were wiping off of the valve openings during the fuel system line cleaning.

 

Yeah,I really wish our transmission didn`t stay in gear longer when cold. It`s very annoying to say the least.Supposedly,they do this to heat up the cats. quicker.(at least that is the MB excuse for this) This is the only reason I give mine a 5 min. warm up before starting off. I don`t like having to deal with that.

 

I hear ya lexus114. It's pretty frustrating, espec here in Canada when it hits -20C in my area frequently. I went to get a code read and nothing pending. I had another one of the incidents where it feels like it's chugging along (took some more notes): There is a shudder when trying to shift from gear to gear. I press on the gas and it sticks at RPM 2(X1000) until I really slam down the gas (which I avoid). It happened this time after I had driven for about 45 minutes, turned the car off for about 10 minutes, and then restarted the car to drive again. hmmm...