NyCrAzY

Thanks for the thread, really helpful! Hmm... that is really imteresting. Do most mechanic shops carry the tools to read out O2 sensors?

Also ... I may just come to the conclusion that its because of my short trips everyday but I have to ask you guys this though ...

1.) How many miles y'all get per 5 gallons? I only get to 58-63 miles before the low gas light triggers (87 octane gas)

2.) What RPM should my car be in when driving between 30-45mph? Mine is usually around 2000.

Just askimg out of curiousity.

Thanks,
Kind regards.

GS4_Fiend

iTrader: (22)

Try using 91, if MPG changes. 91 burns slower than 87.

jbl-1985

Completely agree. Engine must always get to operating temperature in order to operate most efficiently. You have two things working against you - city driving and very short trips to boot.

Just two miles to work? With these gas prices I would ride a bike!

NyCrAzY

Took a trip to Dulles Airport two days ago which is 25mins away from my house consisting 55mph speed limit roads.

& obtained 17.7 mpg! And went back down to 16.4mpg the past day driving to work ... since I assume the car is running rich while driving those 2 miles to work?

Planning to go to NYC soon so hopefully I can obtain 23-26mpg highway readings that Ive seen other members get

carguy07

Was your CEL on during this trip?

NyCrAzY

Nope, no CEL whatsoever.

jbl-1985

18mpg (or 17.7) still is just *not good* imho for highway mileage even with these cars. I'm assuming that there was not a lot of stop and go (were you on the Dulles Toll Road?) My best mileage comes when I set the cruise and sit back and let the car do the driving, so to speak.

Absent any obvious issues with the car, I believe you should be getting low 20's on the highway. Looking back on everything you have done, I still am not sure what else you could possibly do to address this...

mckellyb

I still think you have a failed, or failing, O2 sensor which has merely yet to trip an emissions error.

I've had it happen, before. Took a while to figure out, too, but when the O2 sensor dies, the engine defaults to max fuel, i.e. full rich, all the time.

NyCrAzY

Yeah, I'm still not satisfied. I avoid the toll road due to it's ridiculous rates nowadays. I took Route 7 to Route 28 (it consists of traffic lights, but I wasn't hit with any red lights) so pretty much, it was highway mileage.

It could very be ... but how can I tell since no CEL's are triggered? My emissions are 4 months away, but it'd be nice if I can find out earlier.

Mileage now went down to 15.7 now from a quick trip to McDonalds, lol.

NyCrAzY

Just started the car (12:05am) and my RX300 triggered a CEL.

Will report back later in the morning or afternoon when I go to my local Advanced Auto Parts to get the code read.

NyCrAzY

I got a P0450.

NyCrAzY

Down to 15.3 mpg after work

Leines

Could be wrong but a quick search said P0450 is an evap pressure sensor.... do you have any pending codes as well??? Ive never had that code myself.

Leines

https://www.clublexus.com/forums/rx-...ml#post6847214

Check that thread..someone had a similar problem.. .but with other codes... ive dealt with a P0446 before, but never the P0450 but it appears others on the forum have.... there are a few models that use our engine..so alternatively you can search for the 1MZFE P0450 as well for more results that may be helpful..

Cheers

NyCrAzY

Thanks for the link, bud. Only thing I could of thinked of was my gas cap ... which is already tight.

I just cleared the code and see how it goes from there on.

What exactly is a pending code? How can I check if I have any of those?