Lexmex

I don't know why you'd need it in the United States with the gas quality we have here. I'd just run some fuel injector cleaner like Redline through the system..

IndyRX300

Do you suppose a exhaust leak at the flex pipe could result in a loss of MPGs? After I changed the spark plugs last August or so the mileage went up temporarily. The leak is after the precat O2s which would lead me to believe that it would not be a problem. Unless a loss of backpressure perhaps???

CEL is intermitent now. Sometimes it comes on and most of the time it is off.

Between the Lexus and my car, the cel is going to be the death of me!!!!

Lexmex

What's the CEL?

IndyRX300

Sorry Lex, Check Engine Light. It is the commonly used acronym used on the other forum Im on.

Lexmex

What was the check engine light code that you got?

IndyRX300

I cant really recall but I am thinking PO171 Left Bank Sensor 1???

Money is just very tight and we cant afford 2 replace both repcat 02's

IndyRX300

I jsut confirmed the code from a previous thread of mine. It was infact PO171

Lexmex

When do you notice the CEL coming on?

Sapricot

I finally went to the mechanic and had my fluids changed. They rinsed the ATF, since I couldn't find Toyota branded T-IV and they only had Enios and Mobil 1 (I got the former, being Japanese). I didn't want to mix the different ones. The old fluid had gotten really dirty, though it didn't smell burnt, so hopefully the transmission wasn't actually damaged yet. Taking it easy now for a while after such a deep cleansing. After 20 liters it was still a tad darker than completely new fluid.

Checked the MAF and it was just a bit dirty on one side, other side really clean. Didn't bother checking the other air sensors since I haven't seen any CELs anyway.

They didn't have any of your recommended oils, so I got Enios "pro grade" 5w30. They had a Castrol 0w40 but it was hideously expensive (25 bucks per liter).

Got Redline cooler too, old one was only rated for -30 ºC and that's like the day temperature in Jan-Feb over here ;-)

Mechanic told me I should wait and see if the fuel eco. will improve after the ATF change. Gonna make sure my tire pressure is good first, then run a full tank with the new stuff and see what I get.

Lexmex

Eneos has an ATF that is Type-IV compatible, that's fine there.

I used to buy a Castrol 0W30 (it's a heavy 30 similar to a 40) and it used to cost me $30 USD equivalent a liter in Mexico. Great oil though.

A bit ago we used Eneos 5W30 in our 06 V8 4Runner RWD SR5 and it did a pretty decent job for running a 10000 mile run and great gas mileage (17.3 mpg).

Was the Redline their WaterWetter or the coolant they offered? http://www.redlineoil.com/product.aspx?pid=117&pcid=10

Sapricot

It was a regular cooler I think, small red bottle. Maybe it was a different brand sneakily using "redline" on their product, I'm not sure and I'm not sure it's very important. It's the standard stuff they use here where temps regularly go under -40 ºC in the winter, so I trust the mechanic on this one :P

The castrol was a bit less than $30/L here actually, but the Eneos was about $8...

Lexmex

Let me know how the coolant works out for you. My uncle knew very unique peculiarities about motor vehicles and Mexico City and they worked out well for me in my time there including coolants and that high altitude and environment. Redline also makes a product called WaterWetter, http://www.redlineoil.com/Products.aspx?pcid=10 so not sure if it was that, but that is an excellent product to add to coolant.

Sapricot

Coming back with a bit of an update. Being super freaking cold in the winter here, the coolant has been working fine. I'd have to wait for summer to see if there's any issue with it I think.

What I've found through driving and monitoring the spot rate of fuel consumption is that it might just be the way you have to drive here that's killing the mileage. When I cruise around 50 km/h on the clearer streets I get around 24 mpg now (in October I got around 28) but obviously any acceleration would affect that. I'm guessing that if there weren't any cars around at all I would get something like 18-20 around here including traffic lights.

Is it normal that accelerating a lot would drive the mileage down to 11 mpg? Even when the traffic isn't really crawling along (average speed is high) but is quite jerky I also get the same crappy mileage. I guess what I'm asking is: Is there anything that could need fixing that would only make the consumption higher than it should be under stress but stay pretty normal at cruising RPMs?

I can add that it seems to use surprisingly little while idling in neutral and it's the sudden accelerations and stops that seem to eat all the gas.

Lexmex

Yes, accelerating a lot can throw off the mpg. Gas quality can also affect it.

When I start getting crappy mileage for some reason and everything else is clean (as far as I know), I pull of the battery cables, reattach them, and try not to accelerate for a bit (only normal acceleration off the light, no flooring it), to get my gas mileage back up.

On my commutes I regularly hit traffic and can watch that mpg die down into the low teens.

NyCrAzY

Im still getting 10-13 mpg on my 1999 rx300 @ 177k.

Why??

Things i have done -

- New brakes on the front two wheels
- transmission drain and fill
- rear differencial fluid
- semi synthetic valvoline high mileage oil
- coolant flush and drain
- new tires

Do to list -

- all four struts/mounts (car isnt stable, makes rattling noise, moves a lot when going over bumps)
- transfer case gear oil
- power steering fluid
- brake fluid

Optional -

- rear two brakes