Francis

My wife has been complaining the RX for couple of months. She said the RX struggle from 30mph to 50mph. I am planning to replace spark plug and air filter. What else did I miss?

History: 1). I have 150k miles on the clock,
2). major service from dealer at 90k mile. I forgot spark plug were changed or not at that time.
3). Tranny fluid change at 120k mile
4). Oil change every 7k mile
5). No code found when checking with ODB II

Thanks guys!

salimshah

Call the dealer to check if the plugs were changed or look at the invoice.

Clear out the history by removing battery for 20 min or so.

Play with the shift point change [non-economy if your RX has one .. '99 RX has a switch]

Finally, what are you comparing with?

Salim

Lexmex

What do you mean by struggle?

Have you disconnected the battery cable and let the vehicle reset itself?

Francis

I mean when I try to change lance or pass somebody. I gas but the car accelerates from 30 to 50 mph slower than before. It has been going on for a few weeks. I have never disconnected the battery…should I do that?

Lexmex

I'd do it, because it would eliminate the possibility that it was 'learned' or 'acquired' attribute based on the adaptive nature of the ECM in the RX300 and one's driving style.

Same reason, I'd disconnect it before I went to the track back in Mexico to 'clear' out my commuting driving habits during the week.

Lexmex

Alternatively, if you don't want to lose radio station/clock/seat presets, you could pull out the EFI fuse for about 10 seconds (minute preferable), https://www.clublexus.com/forums/2786328-post15.html and then put it back in, without disconnecting the battery.

Also a free way to try to clear check engine lights.

Francis

So far I have done the following this weekend.

1). clean inlet box
2). replace air filter
3). clean iacv (Thanks tcheung87)
4). Add fuel injection cleaner with premium gas
5). check tranny fluid level and it is accurated

The result: better and I need more tested driving to said it back to normal. Thanks guys!

sktn77a

iTrader: (2)

You might want to pull one of the front plugs. While the front plugs don't necessarily predict the rear plugs, if it's covered in gunk or burned, then all six probably need changed. Good luck with the rear 3!