kiwi

Short term @ idle 1.6
Long term @ idle 6.2

MAF @ idle 3.4 g/s

Air fuel ratio @ 2000 14.7

oxygen sensors @ 2000 B1 S2 .7
@ 2000 B2 S1 .7

this app isn't as easy as i first thought, hopefully that is enough info for you to help me, i can try again if you need more / better.

AussieAuto

Can you get a/f sensor B1S1 @ 2000rpm
a/f sensor B2S1 @ 2000 rpm
Oxy sensor B1S2 @ 2000rpm
oxy sensor B2S2 @ 2000rpm

What model is yours?

kiwi

model is RX330, Sport model.

the torque app is not listing air fuel sensors, and the b1s1 and b2s1 oxygen sensors have no values.

but B1S2 and B2S2 readings at 2000 rpm are .7 volts, same on each side.

AussieAuto

MAF is high, recheck the reading with no accessory's on (no lights or heater or anything) and it should be about 2.7 - 3.1 at most, try cleaning MAF with sensor cleaner, make sure you get down inside and clean the two hot wire coils as well as the single wire at end. Hopefully that should do it...

kiwi

just got the RX back from the shop (minor fender bender)

i removed and inspected the MAF, appeared to be clean, but i thoroughly cleaned it anyway (i have MAF sensor cleaner) and reinstalled.

the wife has it for a few days, so i will recheck readings end of this week or the weekend at the latest.

thanks for the input.

last fuel mileage was 368 km / approx. 66 liters (canada) which equaled 18L/100km

i am seriously considering selling the vehicle. i love it, but i dont really need something this big anymore, and the mileage is just absurd. i will be driving alot more in the near future, considering downsizing to a Mini Cooper.

If i can get it to a more respectable number i would probably keep it, i love this vehicle, and would like to keep it. (2004, with 210,000 km)

RamAirRckt

That is 13.1 mpg down here. Owch. My 94 Fleetwood with the 3.42 gear (7000 lb tow package) never got that bad! I was running 15-16 mpg on E85 in that.

Makes me wonder if the cat converters are plugged up and causing backpressure issues. If it is, that will explain a lot. The problem is the backpressure goes up and the higher the backpressure is the O2 sensors read worse, they appear to read ok, but they are skewed, so it starts making very bad Air Fuel (A/F) calculations. So power drops, fuel economy drops, but the scan tool says all is ok.

and of course, no codes. The idea is the REAR O2 will hopefully flag it as a bad cat. But it measures catalyst efficiency, not flow rate.

Stop by a local muffler shop and see if they would check the back pressure. If over 1 PSI, the cat (cats) are bad. 1 psi is all it takes to skew the O2's

kiwi

i will definitely check with an exhaust shop, it will be worth the charge to eliminate that.

as far as power goes (which i rarely do because i drive like an old lady) its great, the odd time i stomp on it, there is no issue, no hesitation, and just as much power as the day i got it (5 years and 80,000km ago.)

again, air filter good, spark plugs and PCV valve changed out a month ago, oil changed regularly (royal purple gonna change it again in the next week). tire pressure checked monthly, 35 PSI give or take 1 maybe 2 (its hard with the -20-0 celsius)

i'm not shooting for unrealistic fuel mileage. but i would like 12-13 L/100 km city and a little better highway (ideally 10-12L/100km)

LazarusLng

FWIW, the past two fill-ups I have gotten 14.9 mpg(shell premium). I live in Michigan. 95% city driving. I have only owned the car for 3 months. I thought I would get closer to 18mpg city.

ho0n

Perhaps you have an airflow leak somewhere (intake through to exhaust). Even a crack in silicone may surprise you with a significant effect, since there's a lot of air pressure involved in the combustion system.

RamAirRckt

My wife's RX is in the 16 mpg (~14.5 L/100KM) range right now with the low temps 5-15F (-15C to -5C)

Hoping with it is the hard city driving and idling in the cold weather as the culprit right now.

kiwi

checked the readings on the MAF sensor today (i cleaned it out the other day)

let the vehicle warm up, turned off everything, managed to see 3.1 briefly here and there, but it was more steady at 3.2

kiwi

granted so far this tank i have idled a decent amount (waiting at bus stop with daughter for about 10-15min about twice, its minus 20 Celsius)

but i am getting 21L/100 km, outrageous.

i have rechecked the air filter, all good as well as the intake tubes for any blockages, nothing. i also disconnected the upper intake port to the air box (the one with the vacuum operated butterfly valve) so its open all the time, should help with better airflow.

other wise, i am still at a loss as to why the mileage is so bad, and no CEL, and all data appears good.

LazarusLng

Thats about 11 mpg. I hope you can figure it out.

kiwi

did some vacuum leak looking tonight, didnt find anything, searched online as well.

is it possible to have a vacuum leak without a CEL? i wouldnt think so.

AussieAuto

What happens when you reset it on dash or refuel to reset and then drive on hwy? I have an 09 350 and driving 5-6 km back and forth to work sitting in traffic, warming up for a minute or two same temps as you below -5*c and own to -23* for all of feb and I'm usually around 15.6-16.5/L, But when I go for a drive of 100km's or so on the hwy it drops to 12.5- 13/L considering the temps and this time of year that is pretty good, obviously the farther I drive on hwy the better it gets. After refueling and letting it idle for 4-5 minutes I was at like 30/L but driving off it drops pretty quickly...Remember if you are driving through snow consistently it will be much higher...