MichiganRX300

He replaced the cats. I saw old ones, and saw the news ones as RX was still on a hoist when I got there, I was amazed at price differences too. What would cause a "limp" mode, I am thinking a sensor or even a plugged tranny filter. Talked with a buddy from Tower Automotive today and he said it most likely would be a plugged filter. Monday I plan to change out the filter. But will check back here for words of wisdom first.

Update from one frustrated RX owner........ OK, left off as the last posting was RX was going into local buddy, mechanic, who not only charged $300 total to fix the hot cat. problem,including cats too, but had it completed in a few hours. Great prices in my book. With 260,000+ miles on the RX, aparently one of the cats actually came apart inside and "dumped" it's "guts" into the center cat, causing a total plug-up. Guess the engine must have felt constipated trying to expell it's exhaust. Well, it then drives great except for it will not shift into high gear unless it is cold and check engine light came back on too. I do not know the codes yet, cancelled my Toronto trip, and thought I'd come to you guys for some more advice and insight. Plus to share what the "original" problem was relating to the hot cat and lack of speed etc.etc. If RX is cold, it goes through all the gears just fine. Once warmed up, it will not kick into high gear--90% of the time. Any help is of course more than appreciated. Oh tranny was flushed and filled apx. 30-45 days ago too.

No kidding, I just you are in Missiagua, we do alot with Nova Steel and Dofasco Steel. www.gygusainc.com is our site. Small world. We also have a cottage in Sarnia on the river, great offshore boat race party every year there too 100+ people every year. OceanExpress is my uncle, inventor of first composite offshore catamaran. Totally understood about the Cats. now....if they get it up and running I will find some time to contact you. What is best way to contact you and I'll bring the RX by too. Brent 586-246-0799

Thanks for continued input and patience. MAF was replaced last night and nothing changed. Can't see a temp difference with laser gun on right cylinders either. Was told today that Cat. Converts. all need replacement, however cats. are now only $150ea. I said fine, do it, must have car tonight for long business trip tomorrow a.m. in Toronto. Does this sound right?

Update.......took the codes to Lexus dealer, two "techs" and the parts manager said it was Mass Air flow sensor that could cause codes, PO171 and PO330. So got one from them, installed it, and guess what....not a @%*(*! changed. Last night took it over to a very creative buddy of mine who owns a repair shop and he said, "no big deal" and they'll fix it today. I'm wondering what he knows that the other guys do not know including the dealership. FYI, took me almost an hour to go 17 miles and would not go over 10 mph up small hills. Max speed was 30mph on downhill runs. If I pushed on acelerator beyond apx. 15% of the way down it would almost stall out too.

Thanks so much for the quick replies. Autozone tester shows 1st code for O2 sensor, second code shows knock sensor, 3rd code shows same as for O2 sensor. Am I to assume it needs one or two O2 sensors? And how do I know which one to get, they said they could not narrow it down. You guys rock with the fast replies! Thanks!

Full Synthetic, Amsoil, Aylsin Serospace and others are execellent in trannys. Sinc ethe first 1,000 miles on my RX 300 there have been zero problems and I am over 260,000 miles on original equipment. Still in 22-24mpg in Detroit driving conditions. Biggest hing to remember about switching fluids though is oil in engine , if switiching from "normal" oil to synthetic you may find a few new leaks due to the cleaning that synthetics due. So if you can deal with a few oil drips, go for it. I have done this in our delivery trucks, we are a domestic automotive supplier to big 3, in our fork trucks, all all company vehicles. Better rides, better life, and better mpg's.

I have run full synthetic ATF in 99 RX300, and now have over 260,000 on original equipment. No problems due to heat etc.etc. Changed fluid apx. 50-70,000 miles and never had a burned or black color/smell. Additionally have run nothing but full synthetic in the differentials.

A great RX300 with over 260,000 on it, 1999, has served me very well. I have run all full synthetics since the "running in" of the first 1,000 miles. All fluids have been drained on regular basis and filters of course replaced. One of those guys who belives in P/M on your car goes a long way. Anyway, Check Engine Light came on, and noticed a hesitation to shift into high gear. But when car is cool, it shifts just fine. Well it then went into a "bogged" down mode, as though it were starving for air and no excelleration. RPM's were close to 3,000 w/ highest MPH apx. 40. Put it up on a hoist and found that the right cat. convt. was around 500 degrees while the left and center ones were in the 200's. So figured it was a plugged convertor. Went and bought a new one at the dealer for $240 complete wih gaskets. However when going to install the new cat. noticed the old cat. was fine, not clogged at all. I am at a loss, please some assistance to a loyal Lexus guy in Detroit's automotive world.