Saintsfan1

Car runs pretty well for a 22 year old...but..I've noticed some erratic shifting on a recent road trip where if u have to hit the gas while at a good speed like when merging onto a highway, it would rev really high with no burst of extra speed. Also other minor shifting nuances while driving in town. Nothing dramatic but it irks me because I truly like a tight ship. A code came up when getting serviced , it said on my printout : Replace Sensors 234-9021 wideB O2 Sensor Left..verbatim.... I've been trying to make sense of this and learn the lingo but it's confusing a little. I've figured out up and downstream, and left bank is?? Idk...and why is there such a discrepancy in price for the same part #? .from $38 - to $308 !!! Can someone please school me on this. The shop wanted close to $500 and things are tight right now. Saw denso for 126 but I'm not sure 100% which sensor the "wideB, left" description I got is. The shop has flipped it's mechanics and are shady so I don't even want to ask them. Was also wondering if a tranny/diff. drain n fill wouldn't hurt as well. Thanks for enduring this...

Arsenii

Hello,

No cars store their faults in this format, it is borderline useless to be perfectly honest, if that's what you were given by the shop, you will have to look for a different one. A Code Number would be a lot more helpful, any Car Parts Store will rent you a scan tool for free.

Your issue appears to be with one of the Upstream sensors instead of Downstream ones, the difference is that Upstream is located Before the Catalyst, and is a vital tool in adjusting your Air/Fuel mixture, while the Downstream is located After the Catalyst, and is only used for emissions, it doesn't serve any other benefit.

From what is written, it appears that you have issues with a Left sensor. With engines, just like with cars in general, Left/Right are defined when looking from the Back, with LHD cars, Driver's door will be on the Left only if you look at it from the Back, the same with the engines. Look from the Driver's fender to the Passenger, Left would be the Bank 2 sensor, which is the one closest to the Radiator.

To verify that you are about to replace the correct sensor, visit any Car Parts store in the area as mentioned above. Other than that, you can also unplug the Bank 2 sensor and see if you will get any new codes, if not, what is dead may never die..

In either case, Toyota made it relatively simple, both sensors are interchangeable, so you will always be able to swap them around if needed, pain in the neck, but that's why it's easier to all the preliminary work before getting in there. Here is a good place to get them.

Hope this helps and best of luck!

Saintsfan1

Thanks for the info, it helped me get my head around it better. It looks relatively easy to change with the right tool. I'm gonna stop by the AutoZone by the house here and see what comes up on they're diagnostic.
What do you think about doing a tranny and differential flush n fill. I got a 140K on it. My carfax says it was done at 60K? I think?? Just no go hitting the gas but the rpms go up. Anyhow, appreciate it.

Arsenii

I would avoid flushing the transmission in a classic understanding of that term, a safer option would be to drain the pan and fill the new fluid in, doing so a couple of times, driving the car for a few days before each rain and fill to circulate the fluid. When you are on your last drain and fill, drop the pan and replace the filter, unlike older Mesh strainers, those have a Foam insert and they do get clogged.

As for the Differential fluid, unlike in the olden days, they no longer separate both fluids, even though there is still a plug you can use to drain what remains in the differential. In short, replacing the fluid in the Transmission also changes it in Differential, there is no need to worry about it, at least if you do have a 2001 model listed in your profile.

I recently gave in with some of the other members and filled my 2001 ES with Amsoil OE ATF, so far so good, I may be delusional but I am quite pleased with the result, the shifts got noticeably better, even though my transmission is a little far from being perfect at the moment..

Hope this helps and best of luck!

Saintsfan1

Thank you for your input, I really appreciate it. I had just come to the conclusion that I wouldn't flush the trans, just drain n fill. So you helped reaffirm my conclusion. And I also have been looking at Amsoil products. I think it will be ok to just work in a few quarts of synthetic with what's in it now, I just planned on doing it once. I keep hearing that it's a waste of money to do the filter... TBD....I was also interested in the Amsoil engine flush additive..I've done two full synthetic changes but I keep hearing about the sludge problem with older MFZ engines.. Anyhow. Thanks again.