satman99

Wife has 2001 2wd rx300 with 177000 miles that we have owned since new.
The car has been wonderful so far. In the last week it has failed to up shift from 3rd gear to 4th when under mild acceleration going up a slight incline. If you pull over and shut it off and restart it is then OK. It has done this about 6 times recently. I replaced trans fluid and filter with Amsoil synthetic for the 2nd time about 6 months ago. Any ideas??

hypervish

Is there any CEL's or any pending CEL's? Have you tried maybe pulling the battery cables for 20 mins. to reset the computer, and maybe fix itself? How are the shifts?

satman99

Sorry for the delay - had to borrow Actron CP9125 reader - 6 codes
PO171 PO174 PO325 PO330 and pending PO171, PO174. I cleared codes and will test drive tonight after disconnecting battery. Maybe I have an O2 sensor issue? I replaced one of them about 10,000 mile ago and a mechanic buddy said that they last about 100 - 150 thousand miles. The car runs great with no abnormal shifting noticed. The problem has only occurred about 6-7 times.
Thanks in advance.

salimshah

When you put the ignition key in for the first time and move to run (before start), do the cluster lights turn on (cluster warning light self test)? Reason I am asking is that for the problems you list, the CEL should have lit up as your RX settled in limp mode. Maybe your CEL light is bad too.

Salim

satman99

Perhaps I should have mentioned in original post that CEL light was on as well as vsc and the skidding icon. When I put key in and turn it to run all the various dash lights are functional. Since I have cleared the codes the CEL and other warning lights are off now - the car has been driven about 30 miles and so far so good but I think that they will reappear soon - that's the way it acted when the first O2 sensor was going bad. So I'm guessing this is another O2 sensor problem that is also causing a knock sensor and lean condition code? Thanks for your help.
Bob

salimshah

If you have access to a scanner, check for codes again .. you may have a pending (early detection) code.

Part of the debug would be to fix the first code first.

Salim

satman99

I have CEL on, VSC and Trac OFF lights on. Codes are PO174, PO325.
Pending codes are PO171, PO174. So first code is lean condition bank 2 - then knock sensor bank 1. What would you do ? Thanks for your help.
Bob

Gomer1

Any solution to this problem? I have the same exact problem. CEL and VSC are on, and the car, for the last two weeks, occasionally will refuse to shift from third to fourth gear. I turn off the car, start again, and it will shift fine. I have checked the codes and I have 171 and 174. Could this be causing my problem? The car shifts totally normal, so I doubt/hope the transmission is having problems. I know it's an overkill, but knowing the notorious problems with these cars, I change the trans fluid every 10k miles. The car is a 2001 RX.

-Thank you

drdon4u

I have the same exact problem. My RX300 with 160,000 miles shifts very slowly from 3 to 4. I let up on the gas when this happens. Had a Tech look at it while I was on vacation, he said it was a dirty Mass Air sensor (that the one by the air cleaner). He cleaned it and It worked perfect a month and a half. Then it started again and I cleaned it and work for awhile, after that it didn't help so I replaced it. That didn't help. Had the #2 knock sensor replaced to the tune of $800. No help. Once it gets to 4th every thing is OK. Can anyone HELP, PLEASE.

satman99

I have had mass air sensor cleaned as well as knock sensor replaced. Problem seems to have resolved itself as it no longer occurs. I am going to have timing belt replaced in a week or so (197,000 miles now) and will see about eliminating codes that have been on for a year - I have CEL on, VSC and Trac OFF lights on. All of a sudden struts are shot - car bounces like a hobby horse over bumps.