RX - 1st Gen (1999-2003) Discussion topics related to the 1999 -2003 RX300 models

I have a bad gas mileage, how about yours ??

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Old 07-05-14, 11:49 AM
  #256  
HarrierRX300
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Where is the ECI fuse located so I can pull the fuse and reset it too? Thanks.
Old 07-07-14, 05:56 AM
  #257  
driver1988
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Originally Posted by rudymon
eci = ecu ?
my bad i meant ECU yes. the ECU fuses are not hard to find. refer to your user manual
Old 07-09-14, 01:32 PM
  #258  
Eliaquim
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Originally Posted by Lexmex
Where are you seeing the black exhaust?

In addition, which cat are you referring to, there should be two precats off of the manifold and 1 cat underneath the vehicle. The O2 sensor after the main cat underneath the vehicle isn't the key for the gas mileage, that would be the two A/F sensors before the precats.
Sorry but, How many catalytic converters does a 2004 RX330 have? I see two.
Old 08-08-14, 03:41 PM
  #259  
elecinsp
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I have a 2003 rx with 120000 miles getting around 17.3 mpg
Old 09-21-14, 06:41 PM
  #260  
Flexman
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Default Help!!! Only get 11.7 mpg 2000 rx300

Hello everyone, I need your help. I'm only getting under 12 mpg . Mostly city driving. I have the car about a year. Always use super. Water pump/ belt done. No check engine lights on dash . Use liqi Moli for oil. How can I get gas mileage to go up?
Any advice would be very appreciated. Thank you
Old 09-21-14, 07:01 PM
  #261  
salimshah
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Welcome to CL.

Moving thread to an existing thread.

Salim
Old 10-27-14, 09:08 AM
  #262  
matts6887
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i have a 2000 rx 300; and am wondering if its possible to get my mileage up any higher than 20mpg(flat road driving); as my previous vehicle got better mileage.(I have used shell v-power for a few tanks to hopefully help clean the fuel system as well as chevron with techron for a few tanks to try and help as well). I acquired this vehicle with like 107,220 miles approx; and now have almost 110,000; and was wondering if i should use a fuel system cleaner on it. The reason i ask is because it seems like ive been filling up every 6 days as I do a lot of driving from place to place and it seems like im going through gas like no tomorrow. My previous vehicle got better mileage but then again it was a newer vehicle.
Old 10-27-14, 12:08 PM
  #263  
hypervish
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Originally Posted by matts6887
i have a 2000 rx 300; and am wondering if its possible to get my mileage up any higher than 20mpg(flat road driving); as my previous vehicle got better mileage.(I have used shell v-power for a few tanks to hopefully help clean the fuel system as well as chevron with techron for a few tanks to try and help as well). I acquired this vehicle with like 107,220 miles approx; and now have almost 110,000; and was wondering if i should use a fuel system cleaner on it. The reason i ask is because it seems like ive been filling up every 6 days as I do a lot of driving from place to place and it seems like im going through gas like no tomorrow. My previous vehicle got better mileage but then again it was a newer vehicle.
20 mpg -- highway or city?
If highway, at what speeds?
If city, count your blessings, you're a lucky fella!
Old 11-04-14, 08:05 AM
  #264  
Brcobrem
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Originally Posted by matts6887
i have a 2000 rx 300; and am wondering if its possible to get my mileage up any higher than 20mpg(flat road driving); as my previous vehicle got better mileage.(I have used shell v-power for a few tanks to hopefully help clean the fuel system as well as chevron with techron for a few tanks to try and help as well). I acquired this vehicle with like 107,220 miles approx; and now have almost 110,000; and was wondering if i should use a fuel system cleaner on it. The reason i ask is because it seems like ive been filling up every 6 days as I do a lot of driving from place to place and it seems like im going through gas like no tomorrow. My previous vehicle got better mileage but then again it was a newer vehicle.
Hi matts6887,

You did read through all the threads here, right? If yes, then you know to buy a $10 can of MAF spray cleaner and clean the MAF (mass air flow) sensor. On my 2000 RX300, the MAF sensor is right near the air cleaner and easy as pie to get to. Please see my thread and pics here:
https://www.clublexus.com/forums/rx-...ml#post7331333

Regards . . .
Old 11-05-14, 10:20 AM
  #265  
lexus114
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I have come to find that the MZ-FE engine family simply hates winter blend fuel! And they`re not fond of any percentage of Ethanol fuel either. Now my 2GR-FE 3.5 liter is a little more forgiving, but still takes a small hit in mpg`s with the winter blend junk.

Last edited by lexus114; 11-05-14 at 10:23 AM.
Old 11-23-14, 06:29 AM
  #266  
CharBaby
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I'm sure that I have posted here("Bad Gas Mileage" thread) but, I'm not checking so, here goes again.
After getting in the city/town driving of ~18 MPG or so all summer long, this last tank of gas, now that it's colder, was around 15 MPG.

Typically, our CITY summer MPG is right around 18 with an occasional 19 mpg and our winter MPG is 14-15 MPG with 16 MPG being at the top(a good tank).

I have not tried the non ethanol fuel sold at certain stations. This non ethanol fuel is only in higher octane(~91-93) and, the most expensive at the pump
Old 12-03-14, 09:45 PM
  #267  
appsdba
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Hello Everyone,

I just joined the forum this evening. I see a lot of great input.

I was having a misfire issue on my 2000 RX300 (had a P0300 & P0304), which I recently resolved. But now, my mileage is not as great as before & the AVG MPG on my "navigation screen" fluctuates more often than before. I'm wondering if that is normal or if it is adjusting to the changes I made in trying to resolve my former misfiring issue. I used to get 16.4 MPG on average but now I am down to 14.5 and 15. Before I replaced the bad #4 spark plug (which resolved the misfiring), I did the following based on research on various forums like this:

1.) Bought new gas cap
2.) Cleaned out MAF sensor and then bought a new one
3.) Tightened throttle cable until there was no slack (after changing the #4 plug, I loosened it back up as I didn't want to run the risk of running too lean)
4.) Replaced the valve gasket and spark plug tube seals as I saw my #4 plug had oil and my oil was disappearing (call me sick but I actually enjoyed doing this project)
5.) Poured a can of BG-44K in my tank

As you can see, I tried to resolve the issue by spending minimally before blowing big bucks. After all my trials & errors, my RX300 runs great, is responsive and idles quietly & smoothly at a stop light. BTW, the the rest of my plugs are only six months old.

Sorry for the long story but wanted to give you as much info as I had so I could get the best input from all of you who are more experienced on this car than I am.

Best regards,
Carlos
Old 12-07-14, 06:22 AM
  #268  
MarcusF
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Mine was reading 18.5 mpg from when I bought it (a month ago), until I ran the battery empty and it reset, from then it's been reading about 14.5 mpg.
Old 12-08-14, 10:01 AM
  #269  
appsdba
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Thanks for your input, MarcusF. After reading other threads addressing issues similar to this, apparently the onboard computer in our RX300s have a learning curve after resetting the battery or pulling the ECU fuse for a few second. This learning curve takes about 10 days. We'll just have to wait and see.
Old 12-08-14, 07:38 PM
  #270  
speltier
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Originally Posted by MarcusF
Mine was reading 18.5 mpg from when I bought it (a month ago), until I ran the battery empty and it reset, from then it's been reading about 14.5 mpg.
Any DTC codes?


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